Im almost at lvl 20 and I still havent found any gear that is better than the base vault 111 suit you start with. Ofc, I've got like the layered armor on top, but what is the deal with the fact that the starting armor is still the best I've come across?

You're not looking very hard. I hit level 20 last night and have several better under-layers plus all or part of four sets of power armor.

I like the Drifter Outfit to be honest with you. However, taking a base set of clothing and adding some pieces to it helps a lot too. Lately I've been rocking Military Fatigues with all Leather attachments (though my right arm leather is boiled as well).

That is the thing about this game, there are some outfits that are one-piece that have good stats and perk bonuses, but really it seems that the outfits that allow add-ons will eventually give better bonuses. Really depends on what you have or what you can make.

I'm level 54 and still use the vault suit. Upgraded it's definitely the best non-railroad armor. Not sure where you're finding such great armor. Maybe in ballistic damage resistance, not overall.

the vault suits are the only upgradeable clothing (that still leave all slots open for armor) and end up with quite a bit of energy and rad resistance. so in tern I tend to run with combat armor to give me a good bit of all resistances.

that said it does get tiring wearing the same clothes all the time, so at the moment my girl is running around in a white t-shirt, blue jeans, and base combat armor legs (the increase her run speed by 20% and sneak speed by a bit, as well as being stealth coated ) though I play a very sneaky assassin so less weight is good and lack of resistances is not terribly noticed unless things go bad (they usually don't )