They often say they don't use problematic features.

They're still beholden to Google. Their own repo is a set of patches that disable some features. For now, it's mostly feature flags being turned on/off. What happens when Google starts being more hostile and makes disabling features harder ? Can Brave have the manpower to disable that, forever? What if there's a new rendering engine that's 10 times faster but it's so intertwined with a restrictive API that you can't have one without the other?

Brave, for all their talk, are at Google's mercy.

And no, don't give me "but Chromium isn't just Google anymore": it is 90% Google.

I'd expect them to have the skills to fork Blink.

not sure about the resources to support its development long-term, though

That's like people who don't like what Chromium does, but still uses it along with uBlock. It feels to me like the web needs another engine, not chromium reskins, to stay healthy.

it'd be a step in the right direction if one of the "new" browsers trying to do cool things were using gecko (firefox's engine)

I agree with the sentiment. But the main reason I have heard from browser builders is that Gecko isn't as easy to integrate as Blink. Nyxt browser, for example, is engine-agnostic. They still have trouble integrating Gecko. Servo, on the other hand, is designed with embedding in mind. They have picked up some pace after joining the Linux Foundation. Libweb (Ladybird's engine) is also a candidate. Let's hope that current situation spurs them on.

I'd been under the impression that most of the useful stuff from servo had already been integrated back into gecko, but I just checked their git and was glad to see that development continues, despite mozilla's layoffs

right, just problematic people to lead their efforts (brendan eich)

Fair.

On the other hand, didn't he start the whole thing after getting kicked out of Mozilla?

pretty much—according to wikipedia, he resigned, though apparently moz actually tried to keep him around (just not as CEO, his appointment as which flagged the donations initially)

https://en.wikipedia.org/wiki/Brendan_Eich