Yes. On web2 you may need passwords and have to worry about how secure your users passwords may be. With web3 you can assume as a default that all users can use 256 bit keys with near infinite security. This is possible on web2 as well but isn’t feasible as it’s too hard to convince all of society to start using 256 bit passwords on existing platforms, whereas on web3 it’s a pre-requisite.

I mean, we have better with https://webauthn.guide/#registration and the such, which is able to use any TPM for a given system

Should I maintain separate keys per application? What happens if my key is compromised?