15 years ago I made, and even sold, games that I spent less than 50 hours making. But that's with the advantage of starting with a generic template that already held all the game menu structure (achievements, preferences, etc.), and even then the games weren't very good.

If you can make a "production grade … application" (irregardless of language details or anything else) in 50 hours, by hand and without AI assistance, you're an unusual person. Most "agile" places I've been, even a single sprint is longer than that.