I can only speak for myself, and the type of casting and shooting that I do, but for me personally I only see positives.
I cast and lubed traditionally for about 30 years before powder coating. I had several lube-sizers and a container full of various sizing dies. I had it figured out fairly well, and could produce pretty nice traditionally lubed bullets that shot well and almost never leaded. Mostly handgun but a few rifle calibers, nothing real precision and I don't compete, though I can shoot both handgun and rifle well above average for the "average" person.
It was definitely a learning curve for powder coating, frustrating at times until I figured it out. I bought a $10 convection oven at Goodwill, and wired up a PID to control it. I use the shake-and-bake method but don't get too fancy. I love it so much that I sold all my lube-sizers and dies. To be honest, I'm a bit of a traditionalist and part of me wanted to not like powder coating because of that, but once I got it down, it was revolutionary for me. I'm not one to jump on a bandwagon unless it's something that really works.
The advantages I see, for myself, are:
The bullets and ammo are not sticky, no exposed lead.
Noticeably less smoke when shooting.
Size is a bit less important, especially when shooting a common load through several guns, like 9mm.
Alloy is a bit less important, even with magnums.
No leading in "problem guns". I have a couple of guns that have been hard to conquer leading, no matter what I tried. Powder coat= leading is gone.
So what it boils down to for me is that it's essentially cleaner and easier, and works great for my purposes. I can totally understand if someone else prefers traditional lube for their purposes. It's worked well for over a century and will continue to work just fine, if it's what you like.