So I'm assuming you're referring to genetic potential. This is different for everyone, but yes, at a point, strength gains/muscle gains will stall (muscle gains will stop quicker than strength gains, I believe). Again, respectfully, I think the way you're thinking about this is silly. Assuming you're trying to get stronger and more muscular, why would you not want to achieve this in a shorter period of time, in order to maximize your potential? Training once per week is not getting even close to maximizing your potential, and strength/muscle gains will stall very quickly simply because you're not giving your body reason to adapt.
Yes, you're absolutely right, there are hundreds of ways to get strong. But, some ways are better than others, and I'm not at all convinced that training once per week will give you results even close to what training 3-4x per week will give you.
So, in a nutshell, you're limiting yourself by only training once per week. Your body can adapt to much more than that, and I think that lifting more frequently gives you more room for growth.