BobK207 wrote:

It depends on the location of the wall and what kind of "traffic /
use" the wall will see.

Walls that hide pocket doors often have studs turned sideways and they
"work" (well kinda, they're pretty flexible when just covered with dry
wall)

I've built a couple "thin walls" but on the inside of the closet
instead of using drywall, I used the cheapest multi-ply plywood (like
Baltic Birch but not the good stuff).....

Thin plywood (only 1/2") and I ran the stiff direction of the plywood
with the "studs".

You can get plywood considerable thinner than 1/2", like 1/8" or 3/16" (more
of a veneer than plywood).