5e RAW is extremley barebones and only the biggest of contrarians call it a good system.
I call it good at what it wants to be. But yes it is a barebones simple system but that is intentional.
I come from Germany and we got a locally successful RPG that was super complicated (TDE 4.1 edition). Like it had an insanely detailed magic system with countless subsystems that worked completely different like for summoning demons, creating artifacts, each school of magic (elves, witches, druids etc) had own special rules and for combat it tried to model weapon reach advantages from dagger range to pikes or endurance in combat and weapons breaking.
That said I once GMed a combat against a town guard that lasted 14 hours with that system you won't have that problem with D&D.
D&D is neither good for simulating "realistic" medieval combat nor do any of its settings have very well made and described medieval fantasy societies. It is a great system though because of its iconic mechanics & art, richness of its publication history and countless creative options it brings to the table while still being easily approachable for new players.
