Why masks are dangerous...
Masks have almost no positive effects on infection rates (and some negative health impacts), when used in the way people use them at the moment! This is very obvious if we look at infection rates after edicts for mandatory mask wearing in lots of countries. This is not necessarily the masks fault though, more on that later.
Covid19 isn't a very dangerous disease for healthy individuals with a functioning immune system. If you want to protect yourself exercise, lots of fresh air and a healthy diet are way more effective than masks (Taking Vitamin D and other supplements that heighten your immune response are a valid way for short term improvement, but should not be an excuse to avoid the "work"). The risk of dying for healthy individuals below 40 is way lower than 0.1%. If you are healthy and between 40 and 60 your chance of dying is still lower than 1%. Older people have higher risks of dying because at that age, there is virtually no one who does not have one or more risk factors for Covid19. It is no coincidence, that countries with the highest obesity rates (like the US) have the highest death tolls. Obesity equals very likely high blood pressure, diabetes, immune compromised etc. which are all individual risk factors that untreated increase your risk of dying by about 10% for each condition. The 10% number is also applicable for other risk factors, like cancer and auto immune diseases. Alcohol and cigarettes also increase the risk of dying from Covid19, because they compromise your immune system.
Covid19 is very infectious though, which means, that if you give it a chance to slip by your protection, it will infect you.
Cloth masks are basically a potato grader that is supposed to stop wheat flour. That just does not work. That most masks are loose and most of the air does not even go through the mask but is sucked in and pushed around the edges does not really improve the situation.
OP masks are no better. They are designed to catch droplets coming from the mouth, and not necessarily protect from incoming droplets. Aerosols in the air will get sucked in and pushed out around the edges which makes them very ineffective against an infectious disease like Covid19.
Masks that are worn for long periods of time and multiple times without proper sterilization are a potential paradise for bacteria and mold, that in combination with flatter breathing that decreases the capacity to transport mucus, loaded with foreign substances like mold spores, out of the lung and increased humidity behind the mask, can lead to damaging conditions of the lungs.
There are studies from Asia and Denmark that show, that even N95 masks decrease risk of infection by less than 20% in the general population, even when masks are provided in sufficient quantities and how to use them properly has been communicated. For OP and cloth masks this number can then be expected to be in single low digit numbers. The studies I know did not try to select for proper use by shadowing people and selecting for completely proper use all the time to get an upper limit for the efficacy, probably, because that is just not possible to do with an acceptable amount of workload.
If you have risk factors, what masks should you use and how, if you want to have some amount of protection:
You have to wear a high quality mask, N95 or higher that sits tight. You also have to wear (ideally air tight) googles that protect your eyes. Studies show that even people that wear corrective glasses have a statistically significant lower risk of infection, which implies that the virus is able to use every wet body surface (mouth, nose, eyes) to easily infect the body. Do not touch the mask or the goggles under any circumstances, If you do anyways disinfect your hands each time. Under no circumstances touch your mouth, nose or eyes with potentially contaminated fingers from touching your mask or other objects in public spaces.
When you remove your mask, do so with latex gloves (or disinfect your hands immediately after taking it off) and be very careful to not touch your face and especially your eyes. Put both the gloves and the mask in a plastic bag, seal it and dispose of it as bio hazard waste (Throwing it on the ground in public spaces is not a valid way of disposal). Disinfect your hands after you did that. Never wear masks twice.
Your ears have to hurt, if they do not, the mask isn't sitting tight enough and air might get sucked past the mask.
Do shower after every potential contact with infectious aerosols or droplets, basically every time you had contact with other people that might have been infected. The virus has a harder time penetrating the skin but with time, or at small scratches it might still get through.
There are other factors that have way more influence on infection rates then masks. Some of them we can control, others we can not.
One big factor we can not control is weather. High humidity combined with cold and cloudy weather makes it easy for the virus to propagate. Because it can live for longer in aerosols and because it's hosts exposed cold wet surfaces are less prepared to fight invaders. Very dry weather, no matter if freezing cold or hot will make it harder for the virus to propagate. Sunny dry weather is bad news for the virus because of the increased UV exposure and lack of humidity to build aerosol droplets. All that is why numbers dropped last summer, will likely do so again this summer and will likely rise in autumn again, when a then mutated Covid19 strain will propagate, that current vaccines won't be fully effective against. It looks like Covid19 will likely replace the influenza and flue viruses as the prevalent seasonal virus infection.
Social distancing and especially avoiding closed spaces with many people in them is key to minimizing risk of exposure.
Making people believe that masks protect them, if that is not the case, makes people take less care and disrespect social distancing and other precautions, because they believe they are shielded. I see that every time I go grocery shopping. That is endangering the lives of people with risk factors. I am 100% sure that there are children and grandchildren who "killed" their parents or grand parents, because they were made to believe that wearing a mask completely protected them. So it IS very important to be truthful in what is effective and what is not. Especially celebrities, that for many people are a more trustworthy source than media these days, and have a wide platform, do have a moral obligation to spread valid information if they can.