You were talking about a team of 5 cranking this out in about 2-3 months with some longer term part time involvement, with an annual cost of less than 1m and those people mostly all dellivering several product lines ( so actual cost is half or a quater ).
Governments build these kinds of systems ("collect data from a bunch of internal systems and show some public forms and have some internal processes for handling form submissions") all the time. When I worked for a local municipality, we built something like this every other month.
The difference is always having one or two devs who care. Every successful software project I've ever seen has had a few devs who care way more than is healthy