MacBookPro7,1 (mid-2010) in Chrome! It's definitely slower than new computers, but usually I don't have trouble with nice JS libraries unless a page is drowning

MacBookPro7,1 (mid-2010) in Chrome! It's definitely slower than new computers, but usually I don't have trouble with nice JS libraries unless a page is drowning me in tracking software. Just tried it in safari, and it was equally slow (subjectively speaking). Let me give Firefox Quantum a whirl... EDIT: It's actually usable in the newest Firefox! Still kind of slow, but significantly better than Chrome or Safari. But I stand by my earlier point: I'm probably not a total edge case, and if I were designing a tool designed for the public at large, I wouldn't assume that all or even most of my users are on recent, well-maintained computers running recent browser versions. I know people outside of the dev world who (shudder) still run OS X Mavericks and haven't installed a single update in years. People like this will probably use your app, and unless you want them to think it's trash, you have to make it feel snappy.