Instead of being disappointed you could try and analyze why Ruby is lagging so behind Python. Perhaps it's Ruby itself that is the greatest brake and not Python?
After all, people did flock to Python for integration with scientific, math and machine learning libraries, not to Ruby.
Mh, it seems that the Twitter thread mostly focuses on the legacy in terms of language design and then blames much of the demise on there never having been a real killer application that showcased it (as the author pointed out and I agree with Rails worked because of Ruby but didn't showcase it well). I didn't see anything about actually faulty language design.
After all, people did flock to Python for integration with scientific, math and machine learning libraries, not to Ruby.
There are some musings, for example, here: https://twitter.com/zverok/status/1365014133180141578?s=20