If nothing else, I think your conclusion that the product team is incompetent (or displays a lot of incompetency) is debatable. That seems very uncharitable. Reddit isn't flush with money the same way Google, Facebook, Amazon and Netflix are. They can't throw wild amounts of cash at a problem to solve it or attract the talent who can.

I think your characterization of Reddit's infrastructure challenges - which basically considers the problems as solved versus unsolved - is the wrong one. In my opinion, a better characterization would be whether or not Reddit has:

1) the money required to attract talent or buy infra, in order to 2) scale the website to extremely high availability under extreme load, while also 3) doing feature engineering and turning a profit.

This seems like a highly nontrivial problem. Do you know of another website with Reddit's daily active users and revenue profile, but significantly higher availability?

Note that performance is a related but distinct problem from the Reddit UX and advertising. I think that they are probably introducing these kinds of user-hostile changes because they are precisely in the position I've described, and can't find a way to improve performance in the way you're describing.