Before I wanna talk about BP, I just wanna mention something. Last PSL you used the same team in different weeks, and before facing me, I've used BP in my previous match. Yet you still brought the same team, which then obviously didn't work, what were you expecting ?
I've lost this week's match because i made the mistake of using the same team and tactic I've used last week, and got punished for it as my opponent only needed to use Taunt on his Misdreavus, which then resulted in an immediate deserved win from his side, so yeah, poor preparation from both our sides.
Now Baton pass imo isn't banworthy for the sole reason that it doesn't sweep without effort, any kind of set has its requirements and it is a double edged sword.
The most common sets are a combination of Mienfoo ( for Bulk up or Calm mind ), Venonat ( for speed & sleep ), and a finisher: stuff like Misdreavus, Timbur, Clamperl, etc.
Koffing can easily deal with this kind of setup as it doesn't get punished to switch on Mienfoo, and easily Clear smog or Haze, Foongus can clear smog as well and is immune to Sleep powder. Hippopotas is bulky enough to switch on Mienfoo or Venonat and Whirlwind ( if a poke is already asleep ), Vullaby can easily switch on both mienfoo and Venonat and use Whirlwind, Prankster Cottonee is a thing too, Zubat can use both WW and Haze and is a good check for mienfoo and timbur in general, BB, Uturn, Haze, Roost is a nice set that can easily switch on mienfoo, and Venonat.
Setting up while Misdreavus is roaming freely, or while Vullaby is on the field isn't an easy task, and it takes actual skill to perform, I've seen you say recently on discord that " Nothing stops Bidoof from sweeping after it takes an SD from Mienfoo ", but tbh it shows that you're still a bit uninformed about the tier as first, Bidoof's simple doesn't trigger while you pass any stat changes to it via BP, and secondly it doesn't access aqua jet therefore it is slower than Misdreavus, which is at 69% of usage, and other ghosts like gastly, and if Bidoof becomes a thing anyway, Foul play Misdreavus / Gastly will be a thing too, I believe +4 Quick attack doesn't ohko Mienfoo as well so yeah bad exemple tbh.
I'm also interested to see some replays which show that BP can sweep with no effort or skill, maybe then I'd consider reconsidering my thoughts, we've seen many attempts of BP in the past PSLs and I can confirm that its probability of success is always 50/50, if not less ( Senile, Rose, etc )
The last thing I wanna mention is that BP IMO promotes creativity and skill and can sometimes give u a change from the usual balanced teams style of play, that we're all running from when we play that tier, so yeah my 2 Nickels.