Replacing relays as prevention

[CSDentonTX]

So, following along with Robert (DIY) Spinner on YouTube, while working on getting a donor car working for someone, he said, in passing something along the line of "This may be a bad fuel pump relay." He pulls it out, sees a date code he interprets to be from the 1990s, and says "I don't know why people don't replace these old relays."

I posted in the thread asking if he would replace old relays as a preventative maintenance, and he said that he would.

Do you guys do that? There are a lot of relays in there, most of which seem to have different parts than originally. There are lots of blocks in there that I'm not even sure what they are, but at $35 a piece, it could cost hundreds to swap them all out. Are there some key ones that should be replaced just as prevention?