When I switched from PHP to Python years ago I had the same feeling as the OP, then it became the third best, then the fourth, then situational when object-orientation makes sense, then for just scripting, and now... unsure beyond a personal developer comfort/productivity preference. TUIs and GUIs built on Python on my machine seem to be the first things to have issues during system upgrades because of the package management situation.
The saying does not mean that in a rigorous evaluation Python would be second best out of all programming ecosystems for all problems.
The saying means that for any given problem, there is a better choice, but second best is the language you know which has all of the tools to get the job done, so the answer is probably just a bunch of pip installs, imports, and glue code.
It’s kind of like “the best camera is the one you have with you” — it’s a play on the differing definitions of “best” to highlight the value of feasibility over technical perfection.
This myth wasn't even true many years ago, it certainly isn't true today. You can build a mobile app, game, distributed systems, OS, GUI, Web frontend, "realtime" systems, etc in Python, but it is a weak choice for most of those things (and many others) let alone the second best option.