The 4Kids dub was genuinely better in most facets, IMO, for once (it was their very first dub, so they were really forced to ensure it was a success to get on the map + 4Kids weren't able to go the trademark route the company would sadly later take leading to its ultimate demise. Back in the day, the now-defunct company was VERY concerned about faithfulness and such to the source material, you see.
These days though, I would even take their very worst moments with the franchise on the whole, over where the Pokemon dub has been since XY to the close to end of it coming in JN (I won't even bother with the dub to close out the Series already finishing it in Japanese, and I don't begrudge anyone who feels differently, it's not just the music changes or the voice acting that plagues the current English dub's many issues IMO). TPCi in recent years has apparently taken all the wrong pages out of 4Kids' book, guilty of all the same sins but removed quite a bit of their predecessors' strengths w/the dub over time. Elaborating...
The Pokemon dub these days basically has all the worst of both Eras' prior dubbing: the censorship 4Kids was known for being excessive about, basically came back since XYZ in TPCi's dub (e.g. the cross scene, glitter vomit removal), more music is replaced than ever before (to give you an idea HOW bad it has gotten, TPCi did something even 4Kids never did in recent years with the main Series for Pokemon- episodes that are 100% dub scored exist in SM/JN, meaning there is not even ONE piece of Japanese music kept). Say what you will, but this never happened under 4Kids in the first eight years of the dub, even at their lowest point in so far as the Anime goes.
And to add to all of that, TPCi's Team Rocket writing has always been a general sore spot for me when compared to 4Kids' take on them: not claiming 4Kids' TRio was perfect, but generally, you could understand and make out what they said and save Stuart's later goofier delivery as James (which Cathcart honestly retained and made much worse, IMO), generally tolerable. And there's no variation to the dialogue, just a slew of "Totally psyched," "'Kay," mixed in with a transliteration of the Japanese scripts otherwise. 4Kids may have played it a bit too loosely sometimes, but generally, they managed to localize the scripts in a less stiff, more comprehensible way (except M01 and Chronicles, terrible).
Finally, we get to a VERY divisive topic and this is the one that broke the English speaking fandom into contentious arguments for years, the voice acting. I've always had the opinion from the very beginning of the switch, the 4Kids VAs did a generally better job and the initial change put me off more than any Series I'd followed up to that point because at the time, we had the same cast for 8 years straight.
This opinion sadly hasn't really changed despite Natochenny & co doing so for longer by now: 17 years is insane. I will concede Sarah's Ash got quite a bit better over time after being pretty dreadful at the outset, but I think Veronica's Ash was just more consistently boyish and she was able to emote in a more multifaceted way IMO (I actually think Sarah is a better Ash than Delia, though). On the other hand, I never really liked Bill's Brock (though he actually sounded closer to Stuart in BF than for the rest of the Series), and it only got even deeper and even raspier over time (especially don't care for it whenever the character has to flirt, VERY scary for me).
Michele Knotz's Misty actually sounded closest to Rachael's in the Mastermind Special, but it turned into sounding like Eileen Stevens' Iris in the BW flashback, and honestly, in SM it sounded very odd and nasally to me. As for the others, generally like everyone I preferred how 4Kids handled May + Max more, and as for the antagonists, the only time I really liked dub! James was Eric's mid Kanto to mid Johto performance, before Stuart started overacting that part and after Ted Lewis' stiff, too serious wooden James had departed-- but neither of them was ever as off-putting as Cathcart's recent take on the role.
These days, dub! James sounds like a goofier older man with a cold, I'm not sure what they're thinking here but it doesn't work IMO. Michele Knotz's Jessie was all over the place: sometimes, she could sound pretty good, like in BF & BW, honestly it was the easiest change to accept since it at least resembled Rachael Lillis at times-- but in DP, it got excessively high pitched, and from XY onward, it just sounds too valley girl-esque and airheaded (Jessie has serious moments, too, you'd never get that from the current direction though).
Lastly, Meowth, Cathcart actually did a decent job initially up until DP but his Meowth was always quite a bit deeper/gruffer than Blaustein's, and from BW onward, he seems to have leaned all in on the "He's a villain, he's cruel, GRRRRRR" tone and the nice side of Meowth has evaporated in the dub entirely IMO (Blaustein's always managed to strike the best balance between sometimes nice, sometimes mean here, smoother too IMO, even Nathan Price did a better job than JCC these days to me).
And nowadays, many of the things held against the 4Kids dub were also later done by the TPCi dub in recent years, as well. Jelly donuts? Back in M22. Sandwiches? TPCi called apples berries in late BW. Arbok --> Seviper? "Houndoom, move out!" (Houndour). The modern dub is basically take the flaws of both dubs in one package, and it's just not good IMO (I feel bad for the VAs, it's not their fault, but TPCi seems to just treat the dub like a one-and-done deal and it shows: the current lows are FAR worse than the lows 4Kids had, and it never reached the peaks they did either for me).
This is all just my opinion, feel free to disagree, but this is my logic basically.