I wouldn't recommend keeping your TOTPs in Lastpass Authenticator at all. That's worse than having them in Bitwarden given Lastpass's track record. If you want something with cloud sync that isn't your password manager, maybe try Authy? (I don't recommend Authy, but it would be an improvement.)

IMO it makes sense to have most of your TOTPs in Bitwarden - anything that isn't critical. The reduced friction means you're more likely to enable TOTP 2FA for every account that you can - net increase in security compared to not having it at all.

For your critical accounts, I recommend securing them with your Yubikey via U2F / WebAuthn if possible. If not, then use your Yubikeys to store the TOTP codes. If you need/want a better backup than a second device, you could consider literally writing them down or backing them up into a Veracrypt encrypted container. You could also use an open-source, local-only TOTP app like andOTP/Aegis on Android or Tofu/OTP Auth on iPhone.