The 3090 I had was actually somewhat slower than dreamstudio.ai, but the nice thing was the set of python tools I got with it was scriptable so I could do things like create an image, use that as input for another one, and so on, then make them into an animation. There's a bit of tax with initializing python and loading the ML model with each iteration, but if I ever get my hands on a 4090 I'm sure I can solve that.
Well as long as they have a recent-ish NVidia card, rip AMD users.