As an aside, AD has a large number of parts which are non-public. You will not find the part numbers (or any information about them) without an NDA and personal assistance from an AD rep.
I agree that the categorization can be a bit tricky at times, but once you're used to it it's not terrible.
Also often times you'll find some great component on e.g. Maxim's website, only to find no one distributes it, so it's effectively useless in the immediate sense.
As a hobbyist, this sucks so much. With PCB manufacturing reliable enough for high speed signalling being affordable and hackerspaces with soldering ovens in every major cities (and there was some startup - in NYC I believe - that you could give Eagle files and a product order list and they would buy you the components at Digikey and manufacture the board for you... anyone remember their name?!), it really really sucks that all the interesting stuff is hidden beyond such obscure walls.
You won't even find Intel Thunderbolt datasheets on obscure Chinese sites. Wtf? And then Intel complains about why people aren't adopting it?
I don't know about that specific startup, but there are tons of firms in China which will manufacture and assemble PCBs for you. Most of the big hobbyist firms, like JLCPCB, Elecrow, and PCBWay, offer some form of PCBA service. JLCPCB in particular is closely integrated with LCSC, and will source parts directly from them.
Are you thinking of MacroFab (https://macrofab.com/) located in Houston? I believe they have been featured here before.