I just need to be more aggressive and a rider not a passenger
There’s more than one way to ride. Smashing up stuff agressively is a particular style, but spinning in the right gear is also valid. You use your muscles differently and it’s probably more efficient to spin in the right gear.
I got used to spinning having ridden FS bikes for so long, so I rode my rigid MTB the same way. Then when I realised that I could get out of the saddle and smash the pedals it was a great pleasure, and something I’d forgotten all about. I have no issue though with picking a gear on my geared bike and doing it 🙂 I can smash up stuff if I want, or spin, and I can also go fast on the flat and winch up steep stuff. Aren’t gears great? 🙂