There is truth to this (and I'm not criticizing you in the least, just adding 2 cents to the convo). But if we nit pick all the way to the brass bolts, we would have to build our own operating system from scratch (which is pretty much what Start9 has been doing).
There is always going to be some trust factor involved with Self-Sovereignty. Do you verify every line of code of your open source software you select? More power to you, if you do.
Start9 is fully open-source. Their approved apps on their marketplace are open-source. And they make it easy to maintain a server. Not so much for Umbrel.
Ease of use, and a commitment to open-source, are strong selling points for their version of a pre-built.
Thank you for the article!