You and I and a few others on here all started before there were PCs. We have been through custom hardware OS's of our own, to CPM, DOS, MSDos, windows, windows 3.1, windows 95, 98, XP, 7, 10, and now 11. That just picks a few noteable big changes. There is a hundred more in between.
Loss of backward software compatability is a fact of life. You have been through it before and you will get through it again a few more times before it doesn't matter anymore. It will be our grandkids problem then.
I have a few legacy computers too. Slowly but surely they die and force me to move on. I bitch like crazy, but moving on is inevitable. I used to fight it. Now I just bitch. Most important is to disconnect them from the internet. I use external drives to move data on old PCs but never Ethernet. Too much risk of malware getting onto my home network. Firewalls used to be all that was needed. Now it's all a liability. The best protection is to disconnect
Something to be said for the new stuff that will render a 3D airplane while also rendering Satelite imagery in real time. Or rotate a complex 3D CAD model as though you were holding it in your hands.
I went the subscription way with Office 365. I hated to give in, but it has its pluses. At least one of which is the multiple family users each with up to 6 PCs, Phones, Tablets and of course data portability.
It's not all bad John. No pain no gain.