Haven't looked to see if there are other replies yet, but the primary reason, back when I ditched windows completely 20+ years ago, was that the worst that could happen with linux malware or a 'virus' would be the user's home directory becoming compromised. Due to posix permissions they would have no ability to take down your entire system as would happen with windows pretty much all the time if you clicked the wrong button on a pop-up. I still have to use windows for work and from what I see (and from the successful ransomware attacks that have happened due to people opening an email attachment) I can't imagine that has changed a lot.

If you set up system backups of user directories then the damage could be mitigated relatively quickly and easily. These days with flatpaks and browsers (well, firefox at least) having built-in and by-default sandboxing then even your home directory is pretty safe.