What's the point of the omens?

I'm enjoying the change to rituals a lot, since i can buy every ritual an omen... Also, ritual now is more approachable with a fair build, but i don't know what's the purpose of the omens.

They are like to finicky-intricate crafting materials, but some of them are just "your next exalted is doubled"... i think they should be more rewarding, like "your next exalted have greater chance for higher tier mods" or something powerful like that.

Considering the lack of crafting options, omens are the best crafting option we have.

Let's say you are looking for certain prefixes or suffixes. Omens cover that and can save you hundreds of exalts or regals etc.

There are ways to improve alchs, ex, regals. All positive and a net gain over your currency use.

I don't see how Omens can help you craft, please can you put me an example? As my undestanding, a lot of them seems to me like "just put a cherry on top of your exalted/regal".

Prefixes on maps are purely rewarding mods, so it makes sense to use omens to make easy, rewarding maps right now. (I personally think they will have to change this.)
Also, if you want to fracture a 4 mod item, in theory, you might want to max your prefixes or suffixes first since that might be where the "good base" has a highest chance to roll something good.
But yes, the common omens are largely "junk" and you should only waste points buying them if you have nothing better.