Everything isn't always what it's cracked up to be lol. I think a lot of us catfish guys here are just used to the fish we are interested in being mostly sedentary. Like when I got my wyckii I was so excited and intrigued. I planned to watch it at night with a candle lit like I did with the rest of my fish but the damn thing is jet black so I saw only its figure and it wasn't the same, during the day it stuck to its dw unless someone tried resting with it and even then it didn't come out or nothing it just gave them a nip. My excitement died down pretty fast but I still enjoyed having it because let's face it, all the fish I'm really intrigued by are lazy except dorados, gold wolves and lince catfish.
I will say a lot of fish are said to behave differently the more space given, so I still can't wait to keep a wyckii again but with better accommodations. It's said by arapaimag who has kept a few specimens till their deaths after 10+ years, that in 600g and up wyckii are compatible with little issues. Or another example, curupiras are said to become a lot more active in 240g and up where as below they are much more sedentary. Now my curu is much more active than all but one mala I've kept and ofcourse less active than my gold wolf but if that holds true I can't imagine how active he'd be in a 240g.
So what I'm getting at is don't make any official opinions on anything till they're at more mature sizes (I'd say around 12" for vulture probably a little sooner) and in their final home. You also have to consider specimens very in personality.