It is pointless, I agree with you on that at least.
The evolving evidence as far as I can tell was more of a realisation that the mask could likely do more to prevent the virus from getting out than getting in, which I can agree with, basically as it's impossible not to.
But also, as for what you write,
asymptomatic spread is an absolutely massive deal though,
to think it isn't is a big mistake. This means people who don't know they have it, going to supermarkets, offices and the like, mask or no mask the symptomatic are a massive part of the problem.
Someone that has it and has symptoms should be at home, they pose less risk than someone walking around that doesn't know they have it. The guy that doesn't know he has it, wearing a mask is less risk to others, basically because it has to be.
The key thing here though is I don't have access to all the evidence, I'm not an expert in reviewing it, and I believe that people know more than you and know more than me. The thing is I'm willing to believe what they say without digging forever and writing comments which could undermine mask-wearing.