To improve the digital services for citizens you'd first have to be in a position to initiate or convince your superiors to convince their superiors (and so on) to initiate an investment in an improvement. Then wait for about a decade to actually see anything happen.
You don't just show up there all like "if we rewrote this portal in react with all these patterns here (which are really cool, I promise) things would be better for the citizens" and then do just that.
tl;dr if you want to improve the state of public sector software, you're better off entering the domain as a politician rather than software developer.