It looks like Firefox is doing a good service for crypto enthusiast around the world by blocking third party cookies and cryptominers by default:
Not only for crypto enthusiast, but for all regular users who don't know they're being tracked and their privacy is violated.
Chrome is better for HTLM5 Game. Firefox isn't well optimised.
But i use Opera (for game and trading) and Waterfox sometimes.
When website perform better on Chromium-based, usually it's because :
1. It uses google's library/feature which optimized for Google Chrome
2. Website's developer only tested it on Google Chrome
because they're being lazy to safe time
I'm a developer, firefox isn't well optimised. I like it because of the interface and configuration but it's very badly optimised.
I use Opera to develop my games because firefox is slower.