APEX OR FORTNITE?

Without a doubt Apex.

I really dislike Fortnite because of building and how immature the game feels.

In my opinion Apex is arguably one of the if not the best Battle Royale that is currently out. Having different legends to play as allows you to master several different playstyles for the genre, and I really like the weapon variety along with the tiered attachments and other loot. It's constantly being updated to make balance adjustments, and the game feels very polished.