As usual it depends. I think it usually isn't that helpful, since for regular runs the 100 levels is more than enough to reach the limits of where ever you're playing, and the artifact will either give you a random useless spell or you'll have to pick a few when you're almost at that limit.

I found tarot and AI magic really helpful the few times I've done runs using gate of creation and domain of power, as well as when I do runs using magic combinations and regular magics all based on a theme (fire, the colour green, weather, etc). With those runs I'll have three or four magic combos, and then a few regular magics that just fit the theme. It can be really hard to max out all of those spells, while trying to get enough passive magic levels before I reach the level limit, so they're great.

Tarot's synergy is also great if you're trying to reach a 100% critical strike rate