You're not wrong at all, I don't think, as @Bitghost709 said, running a show vs running a game, but I'd say the difficulty of how hard an encounter is does also depend on the player skill.
When you get into hard and tougher encounters the system expects some meta gaming and party coordiantion. It becomes a board game.
When players don't engage the mechanics on that lavel, a medium encounter might be as threatening to them as a hard is for others.
It's the same old difference between yelling "DANGER SENSE!" and "GM: Dex save everyone!; Player: So you're saying I can see the trap?" (Sorry, but it works well as an example.)
Or people still wondering what a bonus action does. (Not blaming anyone, but it shows who has played more and who is newer.)
Those things seem minor, but they add up and leave the party without options sooner or later.
Also, your wish for more creative solutions is definitely hindered when people have only some rules knowledge.
Apart from people who have no knowledge of the rules, who try anything, players who wonder about base mechanics might not try more creative things, because they can't see them, as they're still confused by the basics.
Yup, a story rooted not that dangerous fight can be a fun watch.