Yep, Often
I often build one earlyish if I see my capital is going to be big. The extra cog to my new babies helps their growth considerably. One naturally has to consider district numbers, growth speed and just what civ you are playing.
When settling the colonies a well placed encampment does wonders for defense.
When I have tundra aplenty below me, having a 2 shot city just helps.
When I settle close to teddy at the beginning of the game I just know he's gonna gun for me, such a two faced sod that he is. I'll probably leave it one turn from completion with the city walls also.
When getting another Civ to attack me I will build a troll city near them with walls and encampment 1 turn off completion for that pleasant surprise post declaration.... I love troll cities, they keep me amused. If you troll enough civs like this it seems to increase friendship, not really tracked it but maybe I should. Its that passive aggressive play I love.
When I want to be aggressive agressive they give the extra experience also, a small thing but yes, underrated and a nice discount build card for encampments.
Perfection is not doing something right, its doing it right for you.