I like to discuss/review things, but that usually goes into empty air.
YT preserves my thoughts though.
It also forces me write/compose thoughts in a more orderly and refined manner, since they will actually become videos. When I discuss things I don't plan to make videos of, I'm much more lax and leisure with my writing and thoughts.
It also allows me to practice video editing skills.
And it also allows me to practice my speaking skills when recording myself.
And finally it lets me find people who share my interest and want to converse about it.