Twenty years ago, I would just sit on the ground.
A few years later, I decided the ground was too hard, so I started to take along either a foam cushion, or an old "stadium seat".
In '08, I found an old "fisherman's stool" for a $1 at a yard sale, and started using it. It sits about 16" tall. And I can carry my calls/facemask/gloves/compact binocs/coyote drags all in it.
Then, back in '13, I went to Harbor Freight & bought an aluminum platform "step stool", with folding legs.
Took it home & gave it a homemade camo paint job. Since then...when my health has allowed, it is what I have used.
It too sits about 16".
The reason that I switched to a higher seat, was that I have serious back issues (and I am fat), so it's not easy for me to get down/up from the ground, starting about 5 years ago.