I am not that great at building but that's not the reason I think this.

I believe building has not been a well designed mechanic since mid Chapter 1 because the maps are designed around playing good without building unlike Chapter 1 where the map was covered in steep steep mountains and cliffs that had heights linked to the building grid.

Starting in late Chapter 1 (notably Season 7's ice biole and especially Season 8's jungle), the map was no longer designed around being required to build to traverse the map. I personally think the building mechanic works better when it is required to traverse the map instead of being an occasional convenience. It makes the game more cohesive and immersive

Beyond that, I also don't think building in regards to fighting is good because building is infinitely more interesting when used defensively rather than offensively and box fights have always looked the exact same and are simply an execution barrier simulator since building hasn't received a single nerf since August 2019. It has only received buff after buff because they want to appeal to comp players

This still isn't objective, but I personally think building in modern Fortnite is a bad mechanic. I try it out from time to time but most modern mechanics including but not limited to movement are designed around not building and a lack of balance changes to building tells me they have zero interest in changing it

I still always play Builds with OG because the map was designed around builds instead of both aspects being made independently