I don’t know if you’re talking in the long campaign, same players context, but I often find that for one shots around half of players, at best, skim the rulebook of the particular system. Myself sometimes I do, sometimes I don’t find time. Some people, like it or not, come to a session mainly to chill and even let the others do most of the adventuring. Others engage with the adventure but don’t feel like engaging with the rules beyond what the GM requires.

I’m also assuming the GM will explain the rules, and I think they are the ultimate authority. So stuff from the rulebook may not even be relevant (thrown out, replaced), and GM is the interface for the rules. I would call it OSR mentality, though some may call it glorified player laziness. But as a GM it may give you more room for your ideas actually.

I think the situation is a problem if players don’t know the rules and get mad when their plans are impossible. I suppose this can happen more often with rules-heavy systems.

Anyway, I think keeping the rulebooks close to the players (either as putting them on the table or sharing PDFs) is good advice.