There's some indication of more polish coming, as recently many games have been rewarded (Pressure, Shovelware's Brain Game etc.) from having more polished animations. Devs respond quickly to seeing other games succeed and take notes. The tools are also getting better. It's gradually getting less nightmarish to try to import a working skeletal animation from Blender to Roblox Studio.
Could Roblox games benefit from more polish? Absolutely, but it's less important than having quick access to a high variety of games with consistency in how you play them.
Perhaps the most massive benefit of jank-tolerance is that it lets devs "gradient descent" towards a game players want. If you released a janky proto on Steam, you'd miss your shot, get an "overall negative" review and be done. On Roblox you can release a janky proto, see its metrics, improve over time until you have something people want.