[leovingi]

>Many times you can show useful UI before actual data is fully loaded (i.e. search / filter controls or basic data you already have).

It can be done, yeah, but it has to be handled very carefully because it runs the risk of causing more issues than it solves. I can't count the number of times I've used the AWS Console, loaded a page, clicked on a control, only to find that the data that was loaded a few milliseconds before caused the elements on the page to shift so now I clicked on a completely different button, started the process to load a new page and now have to reload the old one and wait for the entire page to finish loading or risk a misclick again.