I grew up during the dial up era of internet and remember how insane it was each time the technology improved, broadband, dsl, fiber etc.
I wouldn’t expect pages to instantly load, but I have to imagine all the data farming is causing sites to be extremely bogged down.
Most of that stuff is async so probably not a lot. Like, you load the page and it sends a request off to pendo, but the page doesn’t wait for that to finish before doing the next thing.
There are a lot of ways to make pages perform badly, though, especially as they get more dynamic.
At my job the home page was loading extremely slowly for a while until we realized a refactor had made the query backing it extremely stupid. Like it accidentally was doing a separate query for every user associated with every post you could see, and then not even using the results. Oops. Fixed that and got a huge performance increase, but it had nothing to do with data tracking.