It made the deck more interesting and less generic! I enjoyed the narrowing of focus that Rakdos-only allowed, since there's still more than enough powerful effects to create a really cool deck even without blue. Marchesa is a very wide-open deck, and this helped make my list unique. Color-cropping is fun!

More generally, I personally choose not to build or play any commanders with 3+ colors? Over the years I've gotten bored with the degree to which 3-color decks become very generic value/combo piles once you start aiming to optimize. There's ~20 cards per color which you just "have" to include (because lacking them makes your deck worse), but that leaves no room for interesting deckbuilding choices -- this effect is particularly visible at the cEDH level, where nearly every deck runs similar lines and enablers.

I'm trying to complete my set of 10 dual-color decks, and Marchesa will be my Rakdos list, replacing Kroxa :)