It's like saying that we only need chisels and knives instead of power tools. I'd say we need power tools with proper safety features, and thoughtfully built to make them efficient to use.
The particular case of Python is exactly about the lack of harnessing. The same reasons would apply to Perl even more, and equally to Smalltalk or Ruby, etc; cleanliness of the design is not the point. Any of these languages is basically play-doh. You can build anything from it. It will not be very strong, and it's a bit hard to make it into a precise shape. But it's supremely easy to quickly prototype anything in such a language. When you don' have a clear plan, constantly experiment in a REPL, and keep reworking your design several times a week, nothing beats a highly pliable, highly dynamic language like Python.
Then, of course, you have to ship it, and can't afford rewriting it.
There are hyper-powerful languages like C++ and Rust. They are much harder to wield, and C++ famously does away with many safety features for the sake of ultimate flexibility, while Rust goes to great lengths to ensure safety and efficiency at the same time. Rapid prototyping in them is not easy even for top experts.
There are relatively fine middle-ground languages, to my mind: say, Kotlin (or even plain modern Java), or Ocaml (maybe using the Reason syntax), and even Typescript where you can increase strictness gradually while allowing areas in the codebase still in magma state.
But Python, due to its very friendly and human-readabale syntax, won a lot of mindshare by being easy for a beginner, and also by having a nice set of very important libraries (many not written in Python). So we'll see a lot of software that could benefit from being written in a less play-doh-like language, but were started in Python, and will not be rewritten.
Python specifically tries to grow some safety / stability harness, in the form of optional typing and mypy, protocols, etc. It's better than nothing, but it's still far from allowing to write bulletproof code effortlessly.