>> I realize BSOD is no longer nearly as common as it once was

Anecdotally, installing wrong drivers (in my case it was drivers for COM-port STM32 interaction) could make it as common as twice a day on Win11. While my windows server 2008 still doing just great, no BSOD through lifetime.

I agree that for a common user BSOD is now less likely to happen, but wonder whether it's less to do with windows core, and more with windows defender default aggressive settings

It was more fragile 20 years ago than it is today.

It was more robust 5 years ago than it is today.

Or at least that's been my impression. I can't back that up with hard data.