The old Chromecast experience -- choose media on phone, play on TV -- is all I ever wanted. I hate using a remote to browse -- my phone is much better. I hate having my TV logged into an account -- my family, kids, guests all use the same TV and I don't want them using my account, nor do I want to see their account when I'm using it.
The Chromecast protocol is the only thing that the entire ecosystem of Android streaming apps integrates nicely with. I wish Google would open it up to third parties to create Chromecast-replacement devices... but of course they won't. They aren't doing what's best for users, they are doing what's best for their engagement metrics and revenue. And thus, our experience actually gets worse.