Both. It is above average... but also back in its day good dubs were fairly rare, making something like Cowboy Bebop stand out even more than just its obvious quality. And the "real fans always go sub!" weeb crowd mostly didn't notice dubs getting better... because they never stopped reading subtitles and pretending they could understand inflection and nuance in a language they couldn't speak.
Hhm. Dub vs sub huh. I feel like there's no one size fits all answer to that debate. Small or seemingly small changes can have big ramifications for how something is perceived. One common example is how times when there's a quiet moment on screen tend to get filled in with extra, mundane dialogue which can change the scene from a quiet one of drinking in the moment into one of idle or pedantic chatter.
I feel sometimes a dub is better or worse depending on the case. An example of where I think it's good is in Spirited Away. There's a scene where Chihiro is standing outside the bath house and taking it in, in the dub they add in her saying "It's a bathhouse" since a lot of English speakers will likely not know what it is just by looking at it. That's good, makes sense and it doesn't change much. But then there's also the big change at the end of the movie by adding in her talking with her dad about their move and saying, "I think I can handle it", in the original it's heavily implied that not only did she and her family forget the events of the movie, but that they were essentially reset to how they were before they entered the gate. In my humble opinion, this is a travesty of a story decision as the main focus of the story was Chihiro growing up and becoming strong and capable. Deleting all that growth undermines almost the entire movie.
Another example of dub vs sub is My Dress Up Darling, there's a moment after the character Marin realizes she's into Gojo where Gojo is talking with his grandpa about the details of making her cosplay outfit. In the sub, Marin is actually getting flustered seeing how serious Gojo looks when talking about this with his grandpa, she's into the calm intensity he has when focussed on something, but in the dub she says something akin to "What are you doing Marin!? You can't be going gaga for Gojo!" and tries to mentally protest against her feelings by talking about how it's lame talking with your grandparent about something like this. This is, in my opinion, a poor choice for localization. While Marin is a "Gal", a sub culture known for being trendy and glam, a consistent aspect of her character is not caring for societal pressures and sensibilities. The sub follows through on the unique aspect of the character while the dub portrays her as being a much more stereotypically trendy girl that cares about what others think is "cool" or "lame".
So it's just kinda this big ball of "it depends". And this isn't something special to translations either, we've seen how things change between adaptions all the time too.
