Until a major player gets on board. Then it works.
Apple does this by sending an imposter user agent from Safari on iPads.
If only that was expanded to iPhones, too. And then send rotating, or randomized user agents.
Doesn't that just move the goal post though? Instead of using your GPU vendor for the fingerprint they can just hash the output canvas after they a bunch of odd rendering calls, getting a hash from the quirks of your graphics driver and GPU hardware.
Like compare the two form implementations for example. Vinext is a completely different implementation compared to what the Next.js version does. Is their behaviour actually the same? The rewrite looks incredibly naive.
https://github.com/vercel/next.js/blob/b8cbaad24ca66ec673a7b...
https://github.com/cloudflare/vinext/blob/main/packages/vine...
Either way, pretty impressive.
The behavior isn't entirely the same and reaching 100% parity is a non-goal, but there are a few things to note.
This is still a very early implementation and there are undoubtedly issues with the implementation that weren't covered in next's original test suite (and thus not inherited) while not being obvious enough to pop up with all the apps we've tried so far.
As for why it's so much smaller, by building on top of Vite and their react + rsc plugins there is a whole lot of code that we don't need to write. That's where a significant portion of the LOC difference comes from.