You are of course right.

Users of software don’t care for the terms developers use to label their creations, “web app” or “web page” — it’s all the same to them. More importantly, they expect an identical behaviour from both. So when a web app can’t recreate its state from URL it’s breaking a fundamental web UI convention.

Another core UI convention that is often disregarded by web app developers is link click behaviour, i.e. you expect anything that performs a function of a link to behave as it normally would when you click on it with mouse’s middle button, or right click → context menu, or left click with modifier keys (cmd/ctrl, shift). Everyone got used to this and when the pattern is broken it is most annoying.