The point of switching to Firefox is not "Google bad, Mozilla good". The point is to chip away at the chromium browser monopoly. If you have another non-chromium browser to recommend, please share as an alternative.
Mozilla has not proven themselves to be trustworthy, but I think most would still consider them to be less untrustworthy than Google. Firefox offers similar levels of support, feature parity, and performance to Chrome, which makes it an easy alternative to recommend. There are certainly other non-chromium options worth considering, but Firefox is still by far the most accessible.
No PWA support out of the box last time I looked. And Firefox (understandably but annoyingly) doesn't support some of the non-standardised Chrome APIs such as the File System Access API.
Mozilla has not proven themselves to be trustworthy, but I think most would still consider them to be less untrustworthy than Google. Firefox offers similar levels of support, feature parity, and performance to Chrome, which makes it an easy alternative to recommend. There are certainly other non-chromium options worth considering, but Firefox is still by far the most accessible.