Well before Steam's latest update, it was terribad too, their web engine they used could hardly handle a simple website, but I'm pretty happy about the latest update, took them 12 years or so, so maybe Epic will get on it on 2030?
I admit I don't use the in-app browser much, but the times I have I haven't ever noticed problems opening websites. What sort of trouble did you run into?
I play a lot of games where you need the wiki, so I use it regularly. Before the new update it was slow as molasses, I don't know if it was the rendering or some memory management issues, but it was like IE 11 in experience, especially when the site has heavy javascript, but it's decent since the latest update.