I’m experienced in the field of cyber security

So… go lookup the CVEs. Go have a look at what the actual threats against the old device are. What’s the method of attack and do you care.

If you decide you’re happy with the device. Then remember to keep going back and seeing if any new attacks against the device exist.

Whatever happens, we’re not protected against 0day attacks (by their very nature).

I guess there is some reason to worry about “unknown” attacks against the device. But like 0day’s, there’s probably unknown attacks against patched devices as well.

Yeah, I’ll go with name people here and say such with Windows.

If work provide you a machine, then use separate machines for work and home needs. If you’re freelance, when you need to upgrade, plan it well and buy a second machine that is better for gaming/productivity. Now you have two machines and can separate your life.