Firefox is software rendered on linux-nvidia which leads to a bizarre situation of simple web animations lagging on decent computers.

I'd say it's deserved, not FUD. Nvidia did improve in some ways, but it's still way too heavy into blob even in case you plan to use it in the future with nvk. Nouveau / nova developers explained that Nvidia pushed a lot more into their firmware than AMD, turning the kernel driver into more of a shim than an actual driver. That's already a big downside.