There's an another option that can be considered.
You could look at Niquests. It is faster than httpx, but sure be slower than aiohttp in your current code architecture. The pro would be to not drop http2 support and have a better and reliable multiplexed connection. it is also http3 ready, but as far as I know telegram API isn't ready yet. I think that OS trust store native access alongs with DNS over HTTPS mixed with Happy Eyeballs could benefits your users.

Hi. Sorry for the late reply.
Your suggestions are very insteresting!

I would like to point out that PTB is already designed such that it's easy to use a custom networking backend, see this wiki entry as well as the docs of BaseRequest. Using aiohttp or niquests as networking backend is hence already possible.

After discussion in the dev chat, we're not (yet?) prepared to add additional network backends directly in PTB or completely replacing HTTPXRequest. What we would like to propose instead is to make aiohttp and niquest implementations of BaseRequest available through ptbcontrib as a start. This will allow a larger user base to test these rather easily, while not affecting the main lib. @Poolitzer has expressed that he'd be willing to support with this.

If these alternative implementations gain some traction and can maybe even be shown to also perform better than httpx in TG specific comparisions, we're ofc willing to reconsider and add additional implementations to the main lib. I'm mentioning "TG specific comparisions" also b/c in the past we were maintaining a vendored version of urllib3 b/c there were issues with it that were only happening when using it with the bot API and couldn't be reproduced in other settings.

Let me know what you think.

That would be great.
I tried to use my own implementation of BaseRequest using aiohttp as suggested in BaseRequest but wasn't be able to handle different errors.

my implementation

So I would really appreciate it if any of the devs could implement a better one in ptbcontrib

Thanks

EDIT: I updated the code above, and now the errors are handled as expected :)

Thanks @mamad0901-sys,
I used your aiohttp implementation with some modifications.
It works much better. I am able to handle thousands of bots at the same time without any problems.
Whereas before I had connection problems and slowdowns.

Hey. I admit that I had forgotten this thread a bit :/ @mamad0901-sys you're welcome to send a PR against ptbcontrib. I can do some reviews, but doing the implementation on PTB-team side is currently out of scope. We'll still leave this issue open so that people can express their support if they want to.