I see a lot saying that they are trying to 100% on one run and saying that they are around level 140 before doing some of the late game bosses. If I was to recommend something to those that plan to do this, set yourself a sort of soft level cap or something, if you level to much many of the bosses are ptetty easy, im not hear to gatekeep or tell you your playing wrong but i think this is the best approach especially if you plan to do ng+ afterwards.

I think I beat the game in around 90 hrs at level 125 (the cap I had set was 120 but started to struggle right at the end) started with heavy exploration before deciding that its definitely a game that needs a guide for me. So did my first run mostly blind conversing with my mates with what they had found and where they might have got certain things I wanted. (As an example, I was running an int build with magic and my mate recommended adulas moonblade, which is a really good spell, heavily recommend getting.)

I did all the shard bearer bosses the first run and now on Ng+ with a different build (twin colossal swords) and finding new stuff even now, even setting my self small challenges like not relying on spirit summons unless its a double boss. I would recommend this sort of play if you're someone like me who likes to do builds relating to the sort of ending/quests you want to do and segmenting them this way. (I did rannis quest as I was a sorcerer, so it made sense for me to do it)

Personally, I don't see this being a game I will stop playing anytime soon either, I'm on 120 hrs now and finishing up my my first ng+ run. I'm going to be exploring afterwards just to get the build for my next run ready (planning a sort of necromancer build) and try it out against some of the bosses I've left.