I spent a long time as a younger man running general software inside ephemeral VMs. The UX was terrible, but I had no fears about browser vulnerabilities ruining my day. Ephemeral is hard, and the UX is still poor, but I did try it again a month or two back, and it's not impossible.

But now I am doing all my software development back inside ephemeral VMs, AI or otherwise - the UX there is much better, I significantly mitigate supply-chain attack risks, and agents are already constrained to a secret-less, low privilege environment, should I use them. There's a significantly higher likelihood of rogue software in third party dependency trees than there is in a small subset of programs you regularly use.