All it needs to do is to tap into the institutional knowledge already present and shape the future with what equipment we already have.
It means getting back to our roots of doing more with less.
The main issue is this. If AAV's, the future ACV or the MPC can't launch from over the horizon then how do we get them to a point where they can swim ashore?
The Navy/Marine Corps team has already figured it out. You launch your LCAC's from over the horizon, you reach a designated point and then you launch your vehicles from the LCAC so that they can swim onto the beach.
Utilizing this one technique that has already been tested and is part of our playbook can solve the ship to shore problem quite nicely. We'll still need a good swimming vehicle but it won't necessarily have to be burdened to also be a high speed swimmer too.
I highly recommend that everyone read the "LCAC Manual" here...
Note: Yes I know I've already written about this technique, but it bears repeating. Additionally I have found no images or video of this actually being tested, if you find some send it my way.