It would be a little harsh to say that for me playing MUME is a bit like playing the piano on the Titantic as it sinks. However, I guess it is not that far wide of the mark. Presumably some of the graphics capability is stored on the player's machine, like Multiplayer Quake. No fantasy environment comes close to the consistency and depth of Tolkien's Middle-earth. Ed Greenwood's Forgotten Realms has quite a bit of depth but the way it is presented still lacks appeal to me.
MUDs are only one of a variety of games.
The same goes for Sim-game like SimCity, Civilisation, Caesar and Lord of the Realm. They each offer some interest, but these are commercial products and are single-player. This is where I put down everything I want from a game. MUDs have multiplayer in spades. Generic fantasy worlds bore me to tears.