Windows NT on 600MHz machine opens apps instantly. What happened?

A lot of people are bringing up Wirth's law or other things, but I want to get more specific.

Has anyone else noticed how bad sign-on redirect flows have gotten in the past ~5 years?

It used to be you clicked sign in, and then you were redirected to a login page. Now I typically see my browser go through 4+ redirects, stuck at a white screen for 10-60 seconds.

I'm a systems C++ developer and I know nothing about webdev. Can someone _please_ fill me in on what's going on here and how every single website has this new slowness?

Google and Microsoft are the worst for this. When you sign on you can see it flashing through several of their products, signing you on in each, before finally redirecting you to wherever you intended to go.

It might be done for user retention reasons with the idea that people are more likely to use sites they're already signed into, but I really don't need to be signed into YouTube when I sign into my Google work account. Please just skip that and sign in a few seconds quicker.