I keep encountering gripes that people can't "buy" upgrades to new Apple products. No... but you can totally add more RAM if you up your surface mount soldering

I keep encountering gripes that people can't "buy" upgrades to new Apple products. No... but you can totally add more RAM if you up your surface mount soldering skill game. ;) Semi seriously though... you can totally keep old Mac Pros up to date if you machine the heat sinks, patch & flash custom firmware and solder some things to your main board. Laptops & iMacs too. It's not impossible, just harder and seriously out of warranty. We can't achieve miniaturization and faster clock speeds if we keep bulky connectors and forced interconnect design. It takes A LOT to make a CPU upgradable. Memory too. Most automobiles have gone through this. It used to be that an owner of a vehicle could take apart and rebuild their own engine block. You could adjust your timing, fuel pump output, etc. Not anymore. Just as with cars, the average joe cannot work on their own computer anymore. Your crashing and freezing is likely to due with shit software. I'd suggest a full backup, a reimage / full reinstall, and a gradual reintroduction of the crap that's breaking it.