Important correction: "English poetry". It is massively different from the most Indo-European poetry which adds very strict https://en.wikipedia.org/wiki/Metrical_foot rules. In Russian poetry, for example, even a single missed metrical foot violation is considered as a severe mistake and would be noticed by every reader. Also all good poets avoid use common rhymes (also verb rhymes) as cliché (which is considered as a mistake there), while AI tends to use common rhymes by design. There are exceptions (like Russian futurism poetry), but other than that AI fails massively.
I think the concept you are describing is called accentual-syllabic verse. And it definitely exists in English too, it just became much less popular for some historical reason.
I am much more familiar with Russian poetry compared to the English (and I still like it more), but I wouldn’t call violating metrical foot format a mistake in general there. It’s an instrument like any other, which can be used well. Moreover, due to generally having longer words compared to English, you can often see unstressed syllables where a stressed one would be expected by the strict interpretation of the metrical foot, otherwise you couldn’t ever use words with four or more syllables in poetry. I am not an expert but I’ve heard arguments that you shouldn’t use the concept of metrical feet for Russian poetry in general because of that.
You don’t have to look at futurism and other avant-garde movements to see experimentation with the strictness of verses. There was plenty of interesting variations in the Silver age of Russian poetry, and even earlier — you can find quite a few examples of different metrical foot variations and violations in Pushkin’s poems, and even Lomonosov, while preferring highly regular structure, was not above varying it when appropriate.
I do agree with your overall point of AI mostly failing to produce interesting poetry, though admittedly I haven’t experimented much with that. But Russian poetry is much less regular than you describe it.
