Oh I'm so sorry, I didn't see the replies.
It was a mistake because we needed to move fast and figure out if we had something or not. A simple CRUD website (say Ruby on Rails, Elixir/Phoenix, or even straight up Node/Express) would have been faster to build and iterate on.
There was one section of it that would benefit from being able to work while offline, so that could perhaps have been built as a small SPA. But the rest, that was in hindsight a mistake.