Four mana is still a relatively important downside to take into account, though
In my years of personal experience, examining good decklists, and talking to people much smarter than me, 50 mana sources is about the right number for most decks to shoot for, usually 37 lands and 13 ramp sources for a general budget deck
Features the original 1993 Alpha artwork by Sandra Everingham, restored in full playmat scale
In a deck where the goal is to power up Niv-Mizzet Reborn, rather than playing four of the best removal spell in the format, it's actually more beneficial to play some (slightly) weaker removal spells in different colors to maximize the power of Niv's enters-the-battlefield ability
Smothering Tithe [Best White Card Advantage MTG Commander Staple] Smothering Tithe transforms opponents card draw into explosive mana advantage for white decks
Riot Control Riot Control has some surprising utility in Commander given how large board states can become