I think I have an answer to the question of "What is the ultimate martial art?"

I don't think it will come as a surprise to learn I am biased.  Check the URL.

Put simply, one needs to have foundational training in striking, grappling, weapons and internal martial art.  This isn't my idea, its taken from Sifu Kernspecht, but it seems pretty logical.

That said, I don't have time to train all of these things.  I wish I did, I enjoy all of those.

I think you need to pick one of the choices and focus on it.  Get really good at it.  For me, that one is Wing Tsun.  Luckily I have found that the more I learn about WT it increases my understanding of the other areas of martial arts.  Since I only have time to focus on one martial art, I choose WT.  Maybe you read this and go "Yeah, my martial art does all this". Great, though I suspect that much like WT, it emphasizes one aspect over the others.

In that case spend some time learning the basics of grapping - from grapplers.  Etc. In my next adventure I intend to learn BJJ from the local group here in Davis once COVID simmers.