What should take 1 team 1 sprint takes a dozen teams a dozen sprints. Code that shouldn't seemingly otherwise do so can get called in unexpected ways and take down your application. All this "you can do anything" ability leads to abstractions to solve niche issues that makes everything harder to reason about.
A great example: In django, a property on a model object might not be a property. This isn't limited to django, but that is where it bit me. So "customer_record.billing_type". Having loaded the customer_record, one might assume that you could access a property on it with little to no issue. Nope. Python lets you treat that property as a method, and now a hot loop in our code is making a network request to load load more data from a different databases. To prevent this requires mental load, knowing what properties are properties and which are not.
Because in Python, it could be anything, even a boat, and you know how much we've wanted one of those --Peter G.
If you want to throw together some quick thing or toy project or whatever sure, knock yourself out. But I'll honestly never respect people who write large "serious" applications using Python or JS for their backend. There are lots of great languages you can use for a backend. Java, C#, Go, lots of stuff. Js and python are the kind of languages you choose when you either don't know any other language or you don't know that they're ass.
The only good excuse to use JS is that your code needs to run in a browser. The only good excuse to use python is that you're just making a tiny little toy thing. Or you're doing data science stuff/ML, in any case you're not creating a large complex application. And you certainly don't care much about performance.
People invest so much time and money into creating more JS libraries and frameworks and stuff when what we should really be investing time and money into is creating an actually good language for the web. JS is the epitome of sunk cost fallacy.
"But TS" no. TS is just JS with a bunch of overly complicated type bullshit you have to deal with. It is a better dev experience than JS so I do use it, but it's less a cure and more a band aid over the huge, gaping and pus-dripping wound that is JS.
All this kvetching about libraries changing makes me laugh. The Python 2 -> 3 transition was so horrific that the last place that I worked at had a 100M Python monolith with no plans of EVER upgrading to 3. SqlAlchemy 1 -> 2 is an 8 step migration that requires a TOTAL rewrite, and if you break anything, YOUR SITE GOES DOWN. And then people complain because React optionally added hooks or something!
The weird thing is that the internet is full of posts about "The Frontend Treadmill", but no one ever seems to gripe about the converse.