As you say, it wasn't the introduction itself, but the way they did it. The idea of adding extraterrestrials (not gods, that's from Dragon Ball Super) is something that had been seen before, yes, but in Naruto they didn't know how to add it well. Out of nowhere, the ending of Shippuden was to pull out a much more invincible villain, without any introduction, hint, or anything previously mentioned, who turned out to be Kaguya, just to lengthen the series.

The creator has already shown before that he doesn't mind making changes, forgetting characters, and contradicting himself from the beginning. But with Boruto it's clear that what he did was extend the work into something that only served for promotion and to generate more money. When people criticized how similar Boruto was to Naruto at the beginning with its new characters and all that, the creator just pulls out a plot to grab attention. Then, he throws the power scale out the window and Boruto returns several years later being practically invincible, typical of a generic protagonist, but oh well.

I'm a huge Naruto fan and I'm disappointed by how the series has "evolved"—or devolved, whatever you want to call it. But oh well. Nothing in this life is perfect. 🥴