What about a smaller section of a floating dock like jet dock. They are 2'x2' interlocking floating cubes. They are made to have small powerboats drive up on them. Our docks at camp are jet docks and they are gunnel height. Just sit down and swing your feet in!
That is the solution I have seen at some riverside outfitters. They have a dock, fixed or floating, and a floating lower platform a few inches above the water. One on the eastern shore is low enough that you can drive the canoe up onto the dock and simply step out.
On tidal areas they have a short ramp between the upper dock and the lower launch, “hinged” at both the top and bottom of the ramp. I haven’t paid much attention to how they were hinged; at least one was done with sections of old fire hose bolted and fender washers through the boards.
I prefer those low floating docks to the style shown in the Dockdoctor’s link above. The canoe & kayak landing at (tidal) Hammocks Beach uses something similar, but with hard plastic rollers along the angled launch ramp. I use that ramp (no other choice), but I always grit my teeth when loading a composite hull atop the hard plastic rollers and letting it slide into the water.
BTW, when launching a ruddered boat off that type angled floating ramp/dock be
sure to launch stern first; the instant the end of the hull clears the launch the ramp will spring back up and would tear the rudder off. I guess that could also be an ooopsy issue launching boats with a lot of stem layout.
EDIT: Thinking about that some more the one on the eastern shore is unramped and not “hinged”, it is just tied off to the upper dock via the near corners and spring line tethered to keeping it floating a foot of so away. It is a big step down when the tide is out, but doable.