Cube I've been maintaining IRL for about 15 years. It has been through many changes, all based on drafting and player feedback. Three things have remained constant:

-Enough fixing to make the average deck 3 colors, but not so much that everyone just plays every color. Mono color decks of every color and 5-color decks must be viable.

-No strictly worse cards when a better one is available (with one exception: sol ring was replaced by worn powerstone because the former led to uninteresting pick decisions).

-Archetype support is based on which archetypes naturally emerge when I try to put the most generically powerful cards in; Nothing is forced. For example, soldiers and goblins, U/R spells matter, Bant blink, and G/W +1 counters all just kind of happened as a result of including strong cards, so I pushed them more over time, sometimes scaling back when drafters started to feel pushed into an archetype. But B/G spider spawning was never strong enough without putting in too many under-powered cards just to support it, so I left it out.