For a long time, geo has been viewed as something of a basket case of the elements, with Itto being one of the few saving graces.
So is Navi the lord and savior of the geo element that Genshin has long been waiting for since Arataki Itto's release? Not quite. Most people still view geo as perhaps the worst element in the game, and Navi's introduction does not really change much of that. If anything, Navia's kit introduces a way to buff the crystallize reaction, by turning crystallize shards into increased scaling (similar to how Chevreuse can turn overloaded into increased scaling or how Noctis turns hydro reactions into increased multipliers).
But for Navi specifically, as her dps is not high enough to compete with existing units (and she acts more like a subdps), she alone is not enough to make geo as meta as say hyperbloom. If anything, she can be used on several teams as a subdps, for Itto, Noctis, even Xiao, etc. so her introduction perhaps increases the number of possible teams that geo can be played on.
Then what would make geo as meta as say anemo or dendro? Why is anemo broken to begin with? One pillar of anemo supremacy is the vv set, which allows swirl to shred 40% res. A very simple way for geo to be as good is to introduce a god-forsaken set that allows the crystallize reaction to shred 40% res as well. Wow, is that really hard to do? This is one way to buff crystallize.
Another idea is to look at Scaramouche's passive: swirling different autumn elements grants different buffs. Pyro swirl gives atk, cryo swirl gives crit rate, electro swirl gives energy, hydro swirl gives more duration on E.
A similar kind of passive can be made for crystallize: pyro crystallize gives atk, cryo crystallize gives crit rate, electro crystallize gives energy, and hydro crystallize gives say hp. Having a way to buff hp via crystallize can make geo instantly more versatile and useful for hp scaling dps like Noctis, especially if the buff is substantial enough (say 20-30% hp buff).
Very fun, but is this enough to make geo as broken as anemo? Absolutely not. But it would at least make geo better than cryo.
What else does anemo have going for it? Swirl applies the element in an aoe, making it good for shield gauge breaking. Elemental absorption also helps make anemo good at elemental application. But perhaps most importantly, anemo has grouping and cc. So all of these things put anemo leagues above other elements. And currently dendro is probably the closest to anemo in the meta because of hyperbloom.