You speak as if that's unusual...

If it's not something you can stick on an invoice, it's generally hard to persuade management it's worth doing in my experience.

Its the whole point for me: even if I prefer managers that I can convince, I just call that "development". Replace: "feature is done but need to be tested or reviewed" by "feature is not done".

The fall in the technical/developer responsibility anyway for me.

Not just start-ups; larger companies, too. The process may dictate testing, but if, for example, there's an urgent production bug or some enhancement that "needs" to be pushed quickly, testing often falls by the wayside.