I didn’t know Specter or Meltdown can be exploited through a website, that’s good to know.
I should have been more specific on this issue: old hardware is much less common to exploit than old OS or software, so buying new hardware for the sake of hardware security might not be necessary for ones threat scenario. However if there is a risk of a malicious actor accessing or stealing the hardware, then the hardware is definitely relevant.
Similarly I do think one can do a lot with old hardware if they can find a usecase with less needed privileges.