I think Skyrim is overall a very good game and yea i can understand people who keep going back to play it, because there is nothing like it, nothing that allows the sandbox fantasy rpg open world thing. I also keep it on my PC, its one of those games that you should own a copy of.
However with that said Skyrim does have some very poor mechanics or design choices, for example:
1- Level Scaling is awful, it makes progression in the game worse and kills the rewarding feel when you finish quests, kill enemies..etc.
2- Combat mechanics are very basic and dull; The gameplay itself is pretty good but the combat mechanics are boring because you just mash the mouse right click, the enemies have no variety, the boss fights are lacking and very similar.
3- Writing is very weak; the main story is terrible and the writing, dialogue is poor, lacks many fundamental things that makes a good engaging dialogue or quest or story.
4- No memorable characters: another things i didnt like is that there was no memorable character that i liked or could relate to, nobody that made me love interacting or talking with. Serana in the DLC comes close, maybe the best character in the game and that is still an average one when compared to other RPGs.
5- Last one is lack or RPG elements and lack of impactful choices and player agency. You can join all three major guilds and you cant alter the main story in any way.
Still a game having issues doesnt mean its bad or "not" one of the great games. No, Skyrim is still one of the great games imo, i would rate it 4/5. Morrowind is the best and Skyrim is the 2nd best and Oblivion aged the worst of them. Damn so many people here hate on this game, i understand the issues but it seems this game gets more heat than other games, probably some old beef with it. I'm a new member after all. But credit is where credit due, Skyrim is a game that deserves praise, i totally understand people who like it.