Yes! Paraphrasing my childhood:

“Mom, I’m bored will you buy this a new computer game?” “Lol no! Go outside.” “Well crap. I guess I’ll have to write my own game.”

> My new suspicion is now that they didn’t got drastically smarter, but they got trained on the user input on the previous generations.

Yes - that’s one of the ways in which they got smarter. More data more better.

I presume also lessons learned re training procedures, algorithmic advances, but data is a primary lever.