May I ask in what regard? I will say that I'm not an artist, but even so I thought they were about on par with each other.
I am talking about the experience that I and a professional artist have.
At home we have a surface pro 6, an iPad Pro and a Wacom Cintiq.
Me personally, I do not care as much as she does. I use the Surface pen for basic input like drawing in automation or using it instead of the trackpad when I am not at home. I don't draw, I don't edit stuff in Photoshop.
She uses the Cintiq and iPad Pro professionally mostly for drawing, animating, editing. She prefers the iPad Pro over the Cintiq, Surface Pro comes last for her.
I think the best way to describe it is something like: If you rely on the pen simply as a substitute for a mouse, all of them are ok. If you rely on your pen to be capable of expression, the surface pen is simply lacking compared to the apple pencil. Doesn't mean it is bad, just not as good (and that still by a lot).
Of course I did try using all of them for drawing and editing and while I suck at both of those things, it felt way better to work with the apple pencil. And it just feels...different.
Your best bet is probably to check it out in a store for yourself where they have Surface and iPad Pro.
The only problem then is, that's a bad comparison from the get go because Surface only comes with paint and paint 3d which are both very "meh" while the normal notebook-app on the iPad pro lets you do pretty cool stuff already. And when it's a good store, they have Procreate on their iPads and that stuff just rips anything you could install on a Surface a second...USB-A port.
Edit: Like I said, she is a professional. People in her industry generally share her opinion (that includes NA and the EU).