when is a guy ready to be a project supervisor or equivalent
Probably when you are able to hold everyones hand and make sure they can do it the right way. Perhaps be able to think about a week ahead for what you need, when you need it, who is going to do this, how to utilize the time most efficently. Know what youre talking about. Or just say forget it and let someone else deal with all the headaches of babysitting.
If depends on the company and the size of the projects.
Its kinda like you’re never a good swimer untill you try it in the deep end.