In the abstract summary it reads the following:
"Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies."
Therefore yes. But you probably have to wear them properly. Which I do, but many people don't.
It's a statistics game, if you breath out 1 million particles every breath for instance but a bad mask stops 50% of those particles getting out then that's still lowering the abundance of particles in the air.
It is not a golden bullet that will elimanate the virus but clearly if it even stops spread by 10% it is quite a good thing. Don't expect why people think that it's one thing which will stop the spread when it is clearly a conjunction of various thing - vaccines, social distancing, working from home, mask wearing that together.,
It is like when people were complaining gyms were shut. "It's only 4% of the cases why do gyms have to shut when schools are 7% of the cases and pubs are 6%!". Well Einstein it is because if you add up all of those percentages you get to 100% so you have to chose the ones which make a big impact.
Now this here is complete ignorance of science and vaccinations.