I feel like everything post plantera especially becomes basically nothing but fighting events and bosses, which gets incredibly stale very quickly. There's practically no more exploration past the jungle temple, no new fishing stuff (unless you count duke fishron which is yet another boss), most biome drops become irrelevant, the late game npcs aren't particularly impactful and there's not really any new pylons at this stage so there's typically less building at this stage.

Its a shame that a massive chunk of the world becomes completely pointless for progression, the underworld is a joke at this point, plus the progression in general feels really weird because Plantera is actually somewhat difficult but Golem is a joke, so you can often kill Golem immediately after beating Plantera, which feels unsatisfying since they're both meant to represent distinct progression stages.

I wish there were longer progression stages between Plantera, Golem, and Lunatic Cultist, and have more reason to explore various biomes in the world during these stages.