The site is totally unusable right now unless you're a paid subscriber, in which case it's only very slightly less unusable - so by definition I'd say yeah, Twitter as we knew it has been destroyed. Whether Elon intends to backpedal in the next 12-24 hours as seems to be his MO remains to be seen.
It's working mostly fine for me as a non-subscriber.
It's glitched a few times and popped up a "you've hit the rate limit" message on the app, but that goes away with an app restart or refresh of the page.
