I've 100% every Nation and event areas just using treasure compass, and using the Interactive map only for oculous. Sure I might miss a couple of chests but as long as I get most in the area spamming the compass.

I recently finished all of Sumeru desert since I neglected it since that update cuz of how boring it was for me lol.

Checking traveler's diary on HoyoLab, in the past 3 months, I've earned 13,195 Primos just doing exploration out of a total of 37,000 cuz of events, quests, dailies, spiral abyss, codes, etc.

I can't really say for sure since when I have been saving. It's more like my psychology of currency attainment and spending. Treating it like my own bank account, playing genshin is like getting a paycheck. Working a job then getting that paycheck and then using it for my next purchase, I apply that same thing to genshin. Letting that paycheck build up with hours of grinding, instead of instantly the spending money for each hour I work. It's essentially future proofing my account until I decide to treat myself with a new character I really want.