Also, my impression is that people love Iroh, which means I love Iroh
Don't get me wrong, this is a very powerful creature - you can cast it on the cheap if you want to sacrifice nonland permanents, and it can get quite out of hand if left unchecked
Mountains in Magic: The Gathering are a conduit for Red mana, the color of passion, rage, and aggression
Firstly, it's easier to spot a big splashy card that might be good and/or funny in Commander than pinpoint a big player for a more competitive format
It can counter spells or destroy creatures, depending on the number of cards in the opponents graveyard
Even with Lurrus surviving and getting back some random two drop every turn isn't able to cope with a lot of more expensive cards just being in play doing their thing and/or attacking