What I like about TUIs are that they are forced to be simple, and are forced to load all data at once. I don’t prefer interacting with an app in a terminal window, but I do prefer the kinds of apps that are built with these constraints in mind.

There’s nothing preventing web apps from being built this way, but they just often are not.

Could you expand on "and are forced to load all data at once"?

I consider it the frugal man's GUI. Right now looking at top, any time I load a browser tab with Jira content chromium spikes to the top of the list. I'm not even doing anything with it.

Sure but that's just because the Jira website is awful. There's no reason you couldn't design a more frugal version, or a native GUI that was faster.

The way drag and drop and most other updates block all UI interaction until the network response is infuriating.