They're increased, and some things are just obviously slow at least without extra effort to setup things like gpu pass-through. But is it worth basically turning back the clock on your computer's performance a few years to live in a world where a random click from HN or reddit can't quietly compromise your entire computer? I think so.

Probably the biggest thing is to have a lot of ram, because if you're really using the virtualization it's a bit ram inefficient.

Many things I expected to be hard or annoying just turn out to be non-issues. Qubes has lots of good automation to make it pretty seamless to use multiple VMs.

I was already a fedora user, so I just copied my old home into a new app vm and was instantly productive. Then over time I weaned myself off the monolithic legacy vm into partitioned VMs.