Depends which ones. Python? Definitely a source of slowness.
I would first blame the programmers, the design and lack of specialty offloading before blaming any programming language. Well designed web calls scale nearly linearly with usage and usually poor design or programming is the source of slowness. You can always trade language complexity for speed but assuming it is the cause of all perceived slowness is a poor man's view.
It is the same story every time again, first it was java, which has so many large scale projects most people won't even know it's running things they use, now it's apparently python who is to blame for all slowness on the web. When the next JIT or scripted language comes along which is not someone's favourite pet that will get the blame.
I also denounce the notion that trading language complexity for slowness is the case. Python is already complex, and there's some language and frameworks that are actually quite a bit easier to use for web backends. Like java, or dotnet. It just makes no sense to use python for this usecase, even if you ignore the slowness.
But that's not completely true, there is one very good reason to use python. Your devs know it. But, that doesnt say anything about the language itself.
Shhh, don't tell them.
(Kidding, of course.)
The best solution is skin-in-the-game, for-profit enterprise coupled with rigorous antitrust enforcement.
Companies will go a million times faster than open source. They're greedy and will tear the skin off of inefficiencies and eat them for lunch. That's what they do. Let the system of capitalism work for you. It's an optimization algorithm. One of the very best.
But when companies get too big and start starving off competition, that's when you need to declaw them and restore evolutionary pressure. Even lions should have to work hard to hunt, and they should starve and die with old age to keep the ecosystem thriving.
Don't we have enough examples showing that this simply cannot work long-term, because the for-profit enterprises will _inevitably_ grow larger than the government can handle through antitrust? And once they reach that size, they become impossible to rein in. Just look at all the stupid large american corporations who can't be broken up anymore because the corporation has the lobbying power and media budget to make any attempt to enforce antitrust a carrier killer for a politician.
I think it's very myopic to say that corporate structure is the "best solution".
Any example of a politician carrier killed by an attempt to enforce antitrust?
Him putting Lisa Khan in charge of antitrust enraged the tech oligarchs, who then all went MAGA and bought Trump the election.
Didn’t Harris actually raise and spend more than Trump on that election?
And the fact that a 3rd party supports an opponent does not kill any politician's career. Biden retired by himself, following his own party's pressure. And Harris is still around, I believe.