I’ve been a DM for many years, and in all that time I’ve had maybe three players read the PHB. I don’t mind explaining the rules, but it would be nice to not have to remind the wizard how spell slots work (again). Is this a common thing for most groups?
I let the rule-book on the PC side of the table, and expect that player get at least a basic understanding of the rules, especially if they have special power (Like spells/psy/cyberware).
That said, if players struggle to understand the rules, may-be it’s also an issue with the game