When I worked at arXiv we had a math professor on the advisory board who couldn't believe it took us months to roll out upgrades, like he thought he could code up a site like arXiv in a weekend. And he could, except it wouldn't do all the invisible things that the legacy system does.

Remember the goal here is not "make a demo for a site that looks like Fandango" but would be "make something that's truly better in terms of fit and finish and details and that can be proven better in terms of customer success and engagement metrics". AI might help with that, but it's not going to be something an intern can do in two weeks.

Now I wanted to say "it makes it hard that they have to integrate with external systems such as the partner theaters" but actually I think the API economy has offered a way out of enterprise software complexity, see

https://en.wikipedia.org/wiki/Strangler_fig_pattern

but I think most people don't see it that way. Like my belief is that the main difficulty in the API economy is that 20% of API vendors just don't care how hard the client auth experience is, in fact they have an ideology that the best possible life is

https://www.youtube.com/watch?v=o2ObCoCm61s

but boy have vendors like Zapier really intimidated management into giving up 20 lines of simple Python for a "can't get here from there" nightmare.