It would be necessary for reality of the game but devs are so lazy
That's not the way to have things done...
Stamina is a great idea but there is a lot of thing to think about.
First witch attribute for the base stamina value?
Does skills interact with stamina? If yes, how?
Does stamina interact with weapons skills? If yes how?
There is in
OSP a sample codes that add stamina to MP. But for example, the athletics skills add stamina regeneration and ironflesh does nothing to the stamina.
Just coming here and ask for stamina won't help that much the devs.
Come with a design and a complete idea and if the idea is good, I think they would consider adding Stamina to cRPG.