I was also probably 10-20 levels above the "recommended" level most of the game (based on fextralife and reddit posts). But I still enjoyed the game immensely. Plus I was playing with a 2H zwei, so killing smaller mobs in 1-2 hits felt really nice and appropriate.
I didn't get the feeling I saw a lot of people playing with purely str based characters had, that the game is much harder as such character. I started with confessor class, used the lordsworn's greatsword since the moment I found it, and then replaced it with zweihander after I was able to purchase it. I spent the rest of the game with 2 handing the zwei, infused it with a heavy scaling, and level vig/str/end exclusively. Once I upgraded it to +25, it was dealing like 700-720 raw dmg, and staggering 90% of the mobs. Even most of the bosses could be stance broken, including the Elden Beast. I still didn't beat Malenia, which seems to be famous as the hardest thing ever, but everything else was perfectly manageable with the zwei.
I was usually trying to solo bosses for maybe 60% of the game. Then I started using spirit ash summons, as the bosses became a bit harder, and were either too frantic or came in pairs. So again, perfectly beatable with a purely str build (most of the time at least). Malekith broke me, and made me switch from the wolf ash summon which I've been using throughout the whole game to the mimic tear. He was just too fast, and I could barely do one hit per 20-30 seconds in his second phase.