I fought all bosses solo and without any cheesing. I fought them straight on. With proper preparation all bosses are manageable. Ok, you may die during the fight. But that's what portals are for. Again, proper preparation.

This is no game to rush through. If all you care about is boss spanking and fighting, this game is not for you.

The journey is the goal. You explore, you gather resources, you build, you craft, you sow, you harvest. You fight baddies in dungeons and crypts.

You upgrade, you learn new stuff, you expand.

THAT is Valheim. Not a rush to the next boss unprepared and then you get to complain how unplayable it is as a solo character.