The main questionable implicit assumption that is made is that Python can't "the future" (which is severely underspecified without a time horizon) because of what is bad about it today. It even is literally there "Python isn't the future... It can't be" <because something in Python is bad>.
That's highly questionable, because it leaves out - that people appear to have reasons to adopt Python, likely because of something that is good about it, (this complements the observation that not that many people might be impacted by the disadvantages). - that Python and the ML tools in Python might not be static and actually evolve in "the future".
It seems to me a curious lack of reflection substituted for by being particularly assertive about it.
To my mind Python not being the future is more likely to happen if Python becomes less likable or the attempts to improve the shortcomings (which are there, HPy as a medium-term way to get out of the "C extension vs. parallelism/speedup/GIL" corner, mypyc/numba/TorchScript/JAX pushing the "what can be efficiently expressed in Python" boundary) fail.
Julia, Swift, Dex-Lang, HaskTorch all get things right that Python doesn't. But do they get all the things right that Python does get right?
Disclaimer: I'm biased because I like Python and have some involvement in Python ML tools.