If you have a known algorithm for generating those hard-to-read images, then it really wouldn’t be that difficult to generate a large enough set yourself to train a custom ML model to solve them. The same would apply to audio challenges.
Only one person would need to do it then they could share the process, potentially automating others being able to bypass as well.
I like the idea of captcha being open, but unlike encryption as far as I know we don’t have a starting point on something that is actually easier for humans when all information is available. Until something like that exists, open sourcing to implement and improve it doesn’t make sense if you want an effective product.
It doesn’t seem to me like encryption is comparable here. With encryption we have known algorithms that are harder to reverse than initially run. This is a completely different problem, where many inputs are taken and some algorithm has to decide if they are human or not. What digital task can a human do that a robot can’t in the same way, especially if the robot knows exactly the measures it should aim for?
I don’t know why so many people in the fediverse consider Element a competitor to Discord. I regularly use Element, but the non-text functionality just isn’t ready to point people at as an alternative. They will have a bad time and write off Element potentially forever if they are shown that app as an alternative right now.
Some examples of functionality that is important to discord but is not a good experience or is not ready in element yet: voice/video channels, screen sharing, custom emotes and reactions, channel organization and browsing (their latest attempt just doesn’t do it for me).
Additionally, there are times when encryption just has a hiccup still or someone sets it up wrong and things can be messy because of it.
I really like element and they’ve done a good job so far, but It’s just not ready for people to be pushed there from discord.