I’ve been asked what it is. Its principal claim to fame is that it is not Holyhead.
Which is just as well. You can’t drive there, unless you’re a resident: you have to walk, which will give you an appetite for a pint or two in Ty Coch.
But the inability to drive there would have made it difficult to operate car ferries.
Irish waterways history 
I suppose until Telford’s bridge in 1826, you couldn’t drive to Anglesey either; not from the mainland, anyway. And it seems there wasn’t a bridge to Holy Island ’til the early 1500s. But having done a little reading (thanks to your post), it also seem like this wonderful spot could have turned out like Holyhead. Which is to say, a sad end for a coastal town.