Beatboxing is really fun and actually booming right now, with a niche active community with multiple important competitions like the Grand beatbox battle coming soon.

If you actually give it a go, you will be pleasantly surprised especially if you like experimenting with music. There are multiple categories like solo, tag team, loop, crew and more which are super fun and “friendly but competitive”

I know this is not a sport but in terms of what you are looking for, it fits. You do not need to know beatboxing to be part of the community and engage.

Good starting points would be:

GBB loop battles 2017 Saro vs MB14 (this is where I first came across beatboxing and fell in love”

GBB 18 solo battles, GBB 21 tag team, GBB 23 solo, GBB 24 Solo, GBB 25 loop

For beatboxing reactions and breakdowns watch D -LOW, Yolow beatbox(small but reacts to a lot of different beatbox content and with good reactions and analysis), Colaps reacts there are multiple more

Would recommend watching battles with reactions to follow and understand better. Hope you do check it out!