Colorless mana costs for a card can only be met with sources that produce colorless mana, and cannot be met with any other colored mana source, compared to "generic" mana costs which can use any colored or colorless mana source
Mill Mill isnt very common to see at a 4-player table where deck sizes are at least 100 cards, but there are some commander's deck that relies on milling as a win condition
If they dont have removal its effectively card advantage, and you also get information to plan your next steps
My most recent play with Mob Rule was to steal an opponents Rionya after already having a rebounded Ephemerate resolve in my upkeep
That said, your success with a given deck comes down to how its constructed and how you play it
Creatures (26) 4 Ash Zealot 4 Rakdos Cackler 4 Legion Loyalist 4 Foundry Street Denizen 2 Rubblebelt Maaka 4 Akroan Crusader 4 Firedrinker Satyr Lands (17) 17 Mountain Spells (17) If you load up your deck with high velocity, low impact cards you cant afford to only draw a few of them
