Evidence of benefits of air purifiers

I have family who have offered to purchase several air purifiers for their church to make the space safer, and have since gotten pushback from some people on the board saying that air purifiers "don't do anything." DEEP SIGH.

I've already sent some links/info to them to present to the board, but if anyone knows of any really good articles/studies that are fairly easy to digest about the benefits of HEPA filters that I could also send their way, I'd appreciate it.

(It is infuriating to me that a COMMUNITY SPACE is trying to push back on SOMEONE ELSE footing the bill for supplies to help prevent the spread of airborne illness!! We live in the bad place, truly.)