> What government apps do people run?

There are a bunch of them here in Australia, and there were several in the UK.

Here there's a secure ID app for government services which is used as 2FA on the web interface, and various apps to access state and national government services directly. There's a tax one that allows you to scan receipts to collect them up for your annual tax return. In the UK I had an NHS app, can't remember what else.

They aren't mandatory, you can live without them, but they are often convenient.

> Why do you need to access your bank account on your phone?

Because it's many people's primary computing device? Why would you not want to access your bank accounts on your phone?

And because if you want to log on to some banks websites you need to have a 2FA security code which can either be generated by a dedicated security device, which has become less common now, or by an app on the phone which is then usually biometrically protected. There is sometimes a second code-generation method for higher value transfers.

So it is convenient to be able to send payments in the bank app, though less common than using my phone instead of the physical card through apple/google pay (those don't require the bank app to be installed).