Personally, I think it’s a mix of horses for courses and preference.
I’ve got a 29er hybrid, 27.5 full suspension and 26 hardtail, tried a few 29ers as well.
I actually prefer the smaller wheels for more technical, but 29ers are faster rolling.
In a few years I will probably get a 29er marathon bike, for endurance events.
Ultimately, try some bikes and chose the one that you get the most fun from.