Ah, there-in lies the good ole chicken & egg problem. The majority of people won’t sign up until bigger people are on the platform, but bigger people won’t sign up for the platform until the majority of people are on there.
Finally migrated back to Firefox today after a multi year user of Chrome.
What pushed me over the edge? Most of my app icons (keep, pulse, calender, whatsapp) stopped opening in their own windows again.
I had to install the PWA extension in Firefox to get that working again, and it's going to be a slight hassle having to copy and paste URLs from all those windows, but I'm tired of fixing the task bar icons.
Could've gone to Edge since it would work out of the box, but I like Firefox. (except for no native PWA support.)
Edit: found I can right click links in the PWA instances and use the send to other device option to open them in my main Firefox window.
Like the other commenter mentioned, you’re probably thinking of iOS where every browser is WebKit under the hood.
Firefox is open source, so if you still feel that you are correct in your assumption, and you can view it here - there is no Chromium code. Also, chrome specific URLs don’t work (eg chrome://flags) which would be in a Chromium based browser such as Brave.