Isn't the whole approach wrong? All that stuff should be in another thread. That's it. Re-inventing a bad version of cooperative multitasking, in 2025, really?

Isn't the whole approach wrong? All that stuff should be in another thread. That's it. Re-inventing a bad version of cooperative multitasking, in 2025, really? It's surely a nice exercise, but I really hope this is not production code anywhere. If it is then I'm not surprised about the current state of web software (myself working in a very different area, so I don't really have a clue).