Well here's what I think Morrowind's strengths are..
Best story- main story as well as other stories in game especially MQ though, best villains, best design/mechanics of beast races, best Khajiit design for it's time, most interesting world design, best art style, best world design, best factions, best architecture, most vertical exploration, and second most character development after Daggerfall.
Best TES game at having more player skill reliant combat: Skyrim.
Best TES game character creation: Daggerfall.
Best TES game at being challenging: Daggerfall.
Best Dungeons at being challenging: Definitely Daggerfall.
Best combat- if you like more classic old school RPG mechanics- but without pausing in combat, Morrowind and Daggerfall would be tied imo, if you like absolutely despise old school TES combat hit/miss mechanics, then I'd say Skyrim and Oblivion are tied. I think in that case it's Oblivion's more complicated stat dynamic- and more complex magical system, vs Skyrim's dual wielding.
Best magical travel systems: Morrowind.
Best loot placement/system: Morrowind.
Worst TES game if you hate time limits: Daggerfall.
Worst TES game if you prefer everything streamlined as possible: Daggerfall
Worst TES game if player skill is deeply important to you in a TES game: Morrowind.
Worst TES game if classical more typical medieval fantasy is a must for you: Morrowind;
Worst TES game if you feel being nearly omnipotent at max level ruins the game: Morrowind.
Best armor customization: Morrowind.
Best weapon selection: Morrowind followed by... Skyrim. Skyrim brings back crossbows with mods or a DLC, and it brings in dual wielding... Yet Oblivion and Daggerfall afaik didn't even HAVE crossbows, and Oblivion IMO consequently had the LEAST diverse weaponry of all settings. No spears, no dual wield, no crossbows, amongst other things.
Best TES game at remaining challenging at higher levels: Oblivion.
Worst TES game if a lack of heavy stats may bore you: Skyrim.
Worst TES game story: Skyrim.
Worst TES game for a Mage: Skyrim.
Worst TES game faction interactions: Oblivion.
Worst TES game level design: Oblivion.
Worst TES game art design: Oblivion.
Morrowind is my personal favorite, probably not surprisingly. I tried Daggerfall again recently, though I personally didn't like the time limit for quests. Although the dungeons of Daggerfall are amazing, and I like the ship/carriage features a lot. One thing I like about Morrowind that I think is super unique to it and almost defines it, is it's teleportation/magical mobility system.
One thing I disliked about Daggerfall was it being so huge I actually have to click the map to fast travel in a way I see as having questionable immersion. Because so much practically empty space between areas, that you can travel an hour on horseback without seeing a single enemy, building or dungeon. The massive towns and massive dungeons were great though. And while I have complained a lot about Skyrim and Oblivion lacking Morrowind's fast travel system- AT LEAST when you DON'T fast travel, there's not a ton of empty space between destinations unlike Daggerfall.
TES games are never bad though, and largely which TES game you like most is widely a matter of preference and taste.