I think the term is A-B testing. When a company wants to see what effect a change will have, they don’t force it on everyone at once, just on a certain number of people (A), and then see what happens compared to the rest (B).

https://upload.wikimedia.org/wikipedia/commons/2/2e/A-B_testing_example.png

This is why you’ll always get people saying, “Huh, I haven’t seen that. It’s not doing it for me on [browser].” They’re in the (B) group…for now.

The data the company wants is to know if, do the test people like the change (or are at least willing to tolerate it)? Or do they spend less time on the site? If so, how much? If the results are within their predictions, they’ll expand the testing until everyone is in (A).

There can also be A-B-C-D-etc testing, where some people who get the blocking windows would be able to close it, and some wouldn’t. How many of each ended up disabling their adblock?

This also helps to “boil the frog”, where they can slowly get people used to the idea that this is happening, rather than having a whole wave of surprised outrage at once.

I believe Google is “testing” it right now, so for some people it’s been slowly escalating to where they were allowed 3 videos before it stopped them from watching anymore videos with the ad blocker enabled.

Same for me.

Pop up is with 10 seconds timer here. Ain’t nobody got time for that!

Piped/invidious/newpipe/freetube it is.

I just manually blocked the pout with ublock

First, well I’ve been able to get ublock origin to just block the pop-up itself, YouTube now has some scroll event override that locks you to the top of the page. You can’t view the comments or recommended anymore… Not that any value is lost there but still.

Second, the pop-up triggers a “three strike” system where they won’t let you close the pop-up until you disable ublock. That may be easy enough to defeat today, but if YouTube has already gone to these lengths to force you to watch ads, they may eventually stop loading videos altogether until you do.