I would very much like to use a browser that didn't support all the random new web standards (like, I don't know, WebUSB) and rendered most "content" sites good

I would very much like to use a browser that didn't support all the random new web standards (like, I don't know, WebUSB) and rendered most "content" sites good enough. You could still just embed a WebKit/Blink window in order to run web apps. I really liked old Opera and even Edge for their engines that made the web pages feel snappy and somewhat different than the WebKit monoculture.