Thank you for your insight! What about ship size? I don't remember if I saw this previously on HN or if it was a path I went down trying to find out the height of the Baltimore Beltway bridge in Maryland. The issue I came across was that container ships are being built so big now that fewer ports can handle them because of the gigantic gantries that need to be installed and the increased complexity of the automation -- both of which you discuss -- plus dredging, etc. With the smaller ships in the past, a surge in ships could be distributed among more ports up and down the coast, thus alleviating problems like we're seeing. Now, the ships are too big for many ports, which is to the advantage of the big ports/ship-owners who profit from their monopoly.
(I brought up the Baltimore bridge height because, in looking it up, I ran across some articles about the delivery of the new, giant gantries at the Port of Baltimore from China, similar to your Houston example. The ship made its way carefully and successfully underneath the longer Chesapeake Bay Bridge and also the Baltimore Beltway bridge, with only a few feet to spare in both cases. Obviously, this was all carefully coordinated with the local authorities and experts. What I found especially interesting was that the "ship" was also very wide. Very long booms or whatever were stretched out horizontally and perpendicular to the ship. My memory is that these were part of the gantries and they were lowered to further decrease the height of the ship, but maybe the booms are normally this way on the ship to keep it from becoming too top-heavy? [I should watch the YouTube you provided of Houston!] Anyway, this took me off on tangents on the internet reading more and more about the ships and the ports.)
The main constraint for East Coast ports is that they are on the wrong side of the continent from most of the import/export demand in Asia. The Panama Canal isn’t exactly cheap, and some boats don’t even fit in the Canal!
They did recently build out a new expansion of the canal but these problems still remain. What is really cool is the fact that the New York port raised a bridge deck to support the new maximums. https://en.m.wikipedia.org/wiki/Bayonne_Bridge
(I brought up the Baltimore bridge height because, in looking it up, I ran across some articles about the delivery of the new, giant gantries at the Port of Baltimore from China, similar to your Houston example. The ship made its way carefully and successfully underneath the longer Chesapeake Bay Bridge and also the Baltimore Beltway bridge, with only a few feet to spare in both cases. Obviously, this was all carefully coordinated with the local authorities and experts. What I found especially interesting was that the "ship" was also very wide. Very long booms or whatever were stretched out horizontally and perpendicular to the ship. My memory is that these were part of the gantries and they were lowered to further decrease the height of the ship, but maybe the booms are normally this way on the ship to keep it from becoming too top-heavy? [I should watch the YouTube you provided of Houston!] Anyway, this took me off on tangents on the internet reading more and more about the ships and the ports.)