A dedicated laptop solely for work is basic CYA and good practice, everyone should do it.

Yes, even if work doesn't provide a laptop for work purposes and you need to furnish your own. Same goes for phones, etc.

It might be expensive to maintain dedicated hardware to cordon off work from everything else, but it's still cheaper than if you hadn't and the inevitable biological waste impacts the aerodynamic wake generator.

I used to run Qubes on my laptop with one dedicated VM for school. However, I had to change to Windows for a mutlitude of reasons. Might work for some though, and certainly cheaper than dedicated devices.

I go even further. Two completely separate households - one for work, one for personal.

Insert obligatory Severance joke here

Essential if you are an employee. Same machine may be ok as a freelancer.

This is the way.

Not far enough. I have a dedicated internet provider subscribed to a place I rent specifically for work whose address I only use for work purposes, 3 states over. THAT is the way.