One reason is that if you have a link, that link will be copied and sent. Then when the receiver clicks on it, the user has an expectation that they will see th

One reason is that if you have a link, that link will be copied and sent. Then when the receiver clicks on it, the user has an expectation that they will see the same thing as the person that sent it. For the developer that means you have to recreate the state of the app, from the link. This further means that the link must contain all necessary data to do that and the developer has to write more code to recreate the state (sort order of a column in a table f.e.) There are two choices: don't recreate the state -> people will call each other stupid over the phone because they see different things for the same link, -or- Recreate the state -> more money, more time, -or- Just don't have links at all. Which is what people usually choose because is faster and cheaper. What changed was that before, "to do the right thing", i.e. have real links, was the easiest and the cheapest. Now to do the same, you need real developers. Even in Angular there is/was a discussion of where to put the state of the app in the url? put it in the path part of in the hash part? the difference being that the hash is not sent to server. So for search engines all those links are just one actually... Which is ironic because Angular is made by a search engine.