Hello guys, it's been almost a year since I took my last pic, now I want to come back into the photography world but I have some doubts.

I used to took pictures with my Olympus Mark II, i loved the many gears and the portability, but I feel like maybe I've been missing something by using only a micro 4/3.

Is the full frame superior? And if yes, what's better between a Canon Eos 500d and a Nikon D3400? Is my Olympus better than those two full frame options?