This advice is aimed at eventually wanting to hire UI specialists that can fully effect their speciality on your project, product, or service. If you know you'll never have a "UI person" involved, do whatever you want.
How do the thing these days?
You should avoid, at all costs, the situation in which you have two UIs for the same application.
I don't mean an electron app and a web app and an admin app, etc. What I mean is two applications that do similar things that are overlaid on each other.
It also means you don't have much of a choice between client-side, server-side, or prebuilding your UI. Everything has to fit into a two-language pipeline.
Imagine you had two APIs serving from the same database. One serves responses to bootstrap a user request, and then the client transfers over to the other to continue interacting with