> 1) there are now an infinite number of URLs for every one of your pages that may end up separately stored on various services

Sometimes I call this a URL black hole.

In all fairness, black holes are everywhere when you consider that most web servers ignore unrecognized query params for routing. Examine this URL:

https://news.ycombinator.com/item?t=choosing-between-names-a...

Of course the difference is that Hacker News doesn't disseminate URLs of that form, but that doesn't mean someone couldn't pollute the internet with them.