Yeah, the official way from what I understand is basically a container running inside a VM (with multiple containers behind a flag). They run Debian, but I believe there are tutorials for other OS’s if you want to try.
I’ve also heard of people who just replace chromeos with a Linux install, but I think that puts you at more risk of bricking your device.
Passkeys. They’ll probably improve eventually but I feel like right now it’s a mess.
On Android you are forced to use the default implementation, only in 14 and above can you use password managers for them.
On desktop it’s somewhat less messy but you can use the system storage or a password manager extension. Some sites only let you use them for 2FA, some full login, some can’t be put in a password manager from my experience and so on.
Just a mess right now.