Evidence, hmm, well that's hard to come by - I can produce many scientific reports that say facemasks are useless, just as you can produce many scientific reports that say that aren't. But have any rigorous, controlled experiments been carried out by either side? No, of course they haven't - it would be unethical and dangerous to do so. You would have to have a person infected with covid placed in a room with non-facemask wearers; and another person infected with covid placed in a room with facemasks wearers to be able to come up with anything definitive.
So, my main, but not sole, reasons for not believing they work is that:
Newsreporters keep comparing us to other countries where facemasks are generally worn and with lowish covid rates, but omit to mention places like Norway - no masks, virtually no covid; Wales, always had masks, largest covid rates in the UK at the moment; Scotland, always had masks, previously known as the Covid capital of Europe. I could go on....
The MPs don't wear them in the HoC. And before you mention arrogant Tories, a news reporter reported that Labour MPs were just as bad at the recent conference - they only fished the facemasks out when they thought the cameras were near!
Our Queen - I haven't seen her wear one since they were made non-mandatory. Do you honestly think for one minute she'd have been let out of the palace without wearing a mask if she, a (probably) triple-vaccinated 95 year old women, if she was in any danger of catching covid? Honestly?
I remember being very dubious about facemasks when they were first made mandatory, and mentioned it on here, expecting others to agree with me. I was taken by surprise by the hatred expressed toward me and the expectation of my imminent death - yet I'm still here. Never had covid (had an antibody test, so I know for sure). I'm not saying I'll never get it, but if I do, it won't be because of a flippin' facemask.
Also, we spent a weekend recently with some friends and we ruined the whole time by arguing about facemasks. Then, right at the end of the weekend, after me rubbishing their arguments, and they rubbishing mine, they said 'Oh, we don't believe in climate change, though'!! FGS. The point I'm making is that you have your beliefs, I have mine and we're probably all too set in our ways to change our minds. So I'm not going to argue the toss about it any more.