Syncable passkeys do make it easier to handle new devices, but break one of the key values of passkeys - device atteststion. Syncable passkeys are effectively just long passwords as they aren't tied to a device, meaning anyone who gets ahold of the passkey can access your accounts.

At least with syncable passkeys you can't have a website leak your passkey (as they asymmetric keys), but with password+MFA a leaked password doesn't give direct access to your accounts.

My issue with passkeys is that they're tied to devices and ecosystems, and I don't always use the same devices or browsers. I also want to keep work and personal stuff separate. I deliberately store my passwords and MFA in different services so one breach doesn't expose both.

I use different systems for different things. I sometimes work from home and pay bills at work, but I absolutely don't want personal access stored on my work machine.

I've also had passkeys fail to register properly and had to remove them and start over. Even Microsoft documents registration issues.

Maybe passkeys will get there, but between setup issues and keeping everything working across devices and browsers, they're not as simple as they're made out to be. I prefer having control over where my credentials are stored and backed up. Everyone is different, but this new passkey push is not a good fit for me until things get smoothed out.