I think it's better in every way to Pikmin 1 with maybe the exception being level biomes don't feel as varied or interesting as they were in the first.

The dungeons are primarily the focus of this game and I think that adds a lot to it. By focusing more in on gauntlets with more puzzle solving and combat aspects it creates a tighter more consistent feeling experience honestly. I think where the game sorta fumbles with the dungeons is they don't have as much room variation as I wish they did. And by extension of being randomly generated, there were environmental puzzles I just never had to interact with in certain tile sets. They also just don't carry as much visual charm as the above ground areas.

I also seem to remember splitting into two teams being way more important in the campaign too? But largely it's just a convenience more than a necessity.

But still, the bones of Pikmin are strong as hell and charming. The white and purple Pikmin add a fun bonus element to combat with their effects while also helping fill in some holes in your party numbers. They've also just cranked that charm up a little higher. It's always a delight hearing your party cheer and sing as you march on.