I blame Google. Google “contributed” to the HTML 5 standard, and what we ended up with is a standard so complex and convoluted that it’s nearly impossible to make a fully capable browser without using Chromium code.
They didn’t violate open source rules, but they weaponized it to kill off independent browsers. Just my 2¢.
I forgot about HW acceleration. Yeah, that is totally on Mozilla.
But I’ll admit I’m not a web dev. I just took the basic courses in school; HTML/JS/PHP, etc. I learned enough to know I wasn’t gonna be good at it. :)