I may never be able to do this

means that it is possible that I will never be able to do this.

If you want to say

It's impossible for me to ever do this

that's what you have to say.

For example, I may never be able to hit a really good topspin backhand lob. But, on the other hand, maybe I will, if I practice enough.

But to say: I may never be able to play in Wimbleton is nonsense. It implies that there is a possibility that I will become good enough to play in Wimbleton. I will never be able to play in Wimbleton, no matter how much I practice.

I may never be able to do this

means that it is possible that I will never be able to do this.

If you want to say

It's impossible for me to ever do this

that's what you have to say.

For example, I may never be able to hit a really good topspin backhand lob. But, on the other hand, maybe I will, if I practice enough.

But to say: I may never be able to play at Wimbledon is nonsense. It implies that there is a possibility that I will become good enough to play at Wimbledon. I will never be able to play at Wimbledon, no matter how much I practice.