We wanted it to be able to integrate with our backend which lives outside the MS ecosystem. No problem we thought - that's what custom connectors are for. Except they don't work with any of the automated form generation functionality. So we pretty much have to build the form entirely manually.
Low code becomes high code all of a sudden - except it's worse than just coding and learning a new framework. You can't just input your code anywhere you want, or import your dependencies, etc... You have to hunt around in a zillion different (laggy as all hell) interfaces to find the right location where that code can live. Or maybe it's not code - but a toggle somewhere... OMG... kill me.
Good luck if you are trying to learn the lower level aspects... since all the tutorials, blogs, youtube videos - all assume that your data all lives in Sharepoint or some other MS resource - and that your connector actually works as advertised.
If you can code - and your stack doesn't already entirely consist of the MS ecosystem. Just roll your own.