In my experience, people who hold down gyms are high schoolers or college students out for the summer. Hard to compete with them when they have free summers!
I loved the card game.. because it didn't matter if you had the most expensive cards, or grinded through levels. It all depended on strategy. The card game was what Pokemen Go should have emulated, not the Gameboy one.
To be fair, it didn't really emulate the gameboy one either. Very different gameplay.
Well, it doesn't really emulate the gameboy game either, so noone wins.