Yeah, a lot of improvised masks aren't very effective. Which is why I bought a box of KN95 masks as soon as I could. And even after being jabbed I still wear them in every store I go to. And every Drs office and medical facility I go to still requires them.
When it comes to things that have a high probability of damaging or killing me I'm sort of a belt and suspenders guy. I don't like to wear masks. I don't like to wear seat belts, safety glasses, welding goggles and helmets, respirators, heavy gloves, work boots... the list could go on. But the consequences of not wearing any of those when participating in certain activities is - in my opinion - too risky. The annoyance of wearing a mask is minor compared to the annoyance of being incapacitated or dead.
Like any habit, if I don't buckle my seat belt I feel ... funny ... If I walk one step into a shop or even get within visual range of a machine tool and I'm not wearing glasses I feel ... funny ... Now if I take one step away from my truck to go anywhere beside my home or shop and I don't have my mask on I feel ... funny ...
I've found it's easier for me to develop good habits than to fight against and whine about the need to do so. I quit smoking cold turkey by changing my habits and developing different triggering mechanisms, I changed my eating habits by using many of the same techniques. If safety equipment is required I just use it until it becomes a habit.
We have a saying in our shop - "it's just as easy to make good parts as it is to make bad parts". Same thing with habits, it's just as easy to develop good ones as it is to develop bad ones.
IMHO at this point in time for me to wear a good mask in enclosed public places is a good habit to have developed.
What anyone else does is their business.