Maokai support is fun

I'm kinda new, so why is this champion not popular? Is it just my low rank (started in plat 3 this season)?

I played against him once last season, got intrigued, tried playing him, and found it really fun. I haven't played against him since, even in normal. When I pick him in rank, it's usually after enemy support has picked so he's not really a choice.

I just copied the build somewhere since I don't really know much about items and runes yet. I bring heal spell for adc.

Which champions are similar to this one?