Building a feature custom to one company is usually simpler than building an entire product that meets the diverse needs of many companies.

It may very well be that the polished product is a better fit for many businesses than the quickly put together custom feature that does the bare minimum, though.

This. You don’t need to create the first thing in a category or choose something complex to be successful.

You may be able to hack together a basic feature flagging product in 2-3 days, but like many domains, it goes incredibly deep and there’s a lot of hidden nuance if you focus on it. If the value doesn’t drop off for those long-tail “deep” features and people will pay extra for you to handle the nuance - voila, you have an amazing SaaS, potentially.

Oh as a platform it's certainly a different level compared to building something for a set of products (versioning etc for a start). The thing is, if you build something yourself then it's an order of magnitude or two less complex. Unless you have little / no skills in backend.

That's the market; it's shocking (to me) how little knowledge even the largest and most highly rated "Mobile Agencies" actually have with systems which have a lifetime measures in decades vs months. Silly as I've worked with these "wordpress agencies" a lot and they've always been thin/wide skill wise (devs skills which are teachable in a few months but with designers + marketing added to the mix).

Your story is inspiring, thanks for sharing. I hope that I can eventually get over my blind spot as it is a career goal to build a small/medium sized company (with annual revenue around the $1M+ mark).