Let’s say you have 20000 tables in total for a company. They are in 10 different databases. You have no overview over the data and no comments. You don’t have a starting point for where information x are.

Welcome to my reality.

Would I love a data architect and a domain expert in my team? Yeah.

Will I run around booking meetings with everyone that even hints at working with data like a headless hen? Yeah.

Is this the normal procedure for Data Scientists in big and old companies? More so than I would like.

Oh! And I forgot that the security department will constantly deny your access to data you need (until you force their hand).

Everything you mention is true and is compounded if the data healthcare related. Privacy concerns, data from different systems that claim to be the same. Preventing reidentification.