This is exactly how I don't want to build my apps.

As much logic on the backend as possible makes it easier to prevent concurrent changes, support multiple frontends, debug while having the whole env under control etc.

This week, I learned that our website's homepage has 40 megabytes. Another frontend maximalism. :/

I couldn't disagree more with this take. Frontend maximalism locks you out of so many wins. I'd never consider it outside of a solo offline app and at that point a native app is probably a better choice.