My father is an entrepreneur who needed to invoice his clients. I had no idea how he managed to do invoicing until I made him a very crude invoice template using Microsoft Excel / OpenOffice. That served him well at least 10 years. The excel invoice template was not the most intuitive to use,so over the years I've been on a help desk call with my father countless of hours. No video or screensharing, just trying to guide him using Excel via phone call.
Eventually, my personal support hour limit ran out and I decided to build a very simple invoicing app in order to decrease my monthly help desk calls.
I built the first version in few evenings and managed to get it to a MVP'ish stage. I showed it to my dad, and watched him create an invoice with it. Let's just say that my first version did not survive the head-on collision with a customer.
Over a period of few weeks, I fixed bugs and build few more features. I constantly showed the new version to my father and he finally agreed to use it without me lurking behind his back.
Not sure how far he got creating his first invoice, but unfortunately, he decided to switch back to Excel and that damned invoice template.