There was even a famous ad campaign back in the day with the tagline "You are a Planeswalker." While the story would talk about Planeswalkers in card names and flavor text, we never actually made a card that represented onethe closest we got was Invasion , which was Urza in disguiseas we felt they were too powerful to be represented as a card
Id also suggest all ten Ravnica Signets, Chromatic Lantern, Coalition Relic, Fellwar Stone, Network Terminal, or many other artifacts that tap for extra mana that are better of a rate that Altar of the Lost
It completely redefined the Combo Coveted Jewel Shops deck, making it more resilient and powerful, and has simply become one of the best effects like this in the format for decks that can cast it, especially those decks with Mishra's Workshop in them
Zodiark, Umbral GodZodiark, Umbral God Monoblack decks have a lot of powerful cards and strategies at their disposal in Commander, and having a removal spell in the command zone like Zodiark, Umbral GodZodiark, Umbral God is sure to terrorize your higher bracket Commander pods
If this type of effect was good enough, we would likely see more reanimation splashes or people playing Seveinnes Reclamation , which isnt really happening
Token makers like Retrofitter Foundry can be repeatable, and cards like Hop to It and Glimpse the Impossible can make three tokens with one card, so efficiency is the name of the game