When foam wings were just starting to appear, people found out fast that foam wasn't really very durable without protection. It needed to be protected from just about everything. I think the experienced builders/flyers who tried foam wings actually never even considered or tried to glue hinges into the foam. I know I never saw plans for any hinged parts that didn't have wood to support the hinges. The TEs were either deep enough or there were balsa inserts where the hinges went.

That's pretty amazing.

Back in the day, modelers had to learn how they were doing as builders from their crashes and structural failures. Today we don't have that opportunity with ARFs. But we still have to learn what works and how to build ARFs that will last as long as we will need them to last.

Same hobby, but with different stuff to learn.