Is it? I find a lot of these performance views are very subjective depending on multitasking, hardware, gpu, extensions, etc. Chrome has always served me well, and the built-in sync and consistency on mac + windows is what I like best. I would rather compete on features and general standards compliance, and then let people choose their own experience on top.

When everything else runs silky smooth, using vanilla Chrome on vanilla macOS feels like a giant slug. For something so fundamental, I find it baffling Google is unable to do it properly.

You're talking about Google's own product. Chromium is open source and all that "bloatedness" can be taken out. There are already many companies out there that use the Chromium rendering engine have already taken the unneeded bits out and customised the browser with their own features.