Exactly correct!! My 12+ year old AMD FX-8350 is running the latest version of Ubuntu Linux with Linux Kernel 5.17 installed.
An older SSD drive for the OS, WiFi, Bluetooth and an NVIDIA Graphics card that's at least 5 years old for video.
In short: it screams. It has 32Gb of memory and 10TB of storage attached to it that I used for backups from my other machines.
Old hardware with Linux is typically just fine!
And as Big Tech obseletes your hardware forcing you to buy new every three years, you can still have a functional computer that is more secure.