Gerry McGovern asks:

Any good digital designer knows that architecture and hierarchy have a very significant influence on how people behave on a website or app. Yet getting designers and orgs to truly focus on architecture design is so hard. Why is that?

Well...

The answer is multi-faceted of course. Aspects that are in play:

As such, architecture is the outcome of a group effort, not a specific role. Shared responsibilities are often hardest to take care of.

I personally love working on this UX plumbing level of things, it's where the potential for what the thing may become gets defined and realised.