Hi Slab,
I think ou mean Winging vs Windsurfing. Foiling can be added on to practically any water borne craft, be it wake, surf, wind, wing, kite whatever.
The two sports are very different and wind surfing is much easier to learn and progress on. A Windsurfer LT can see you up and sailing along within the first hour. Wing foiling is much harder to get to the part where you are having fun ie flying controllably on the foil.
Windsurfing is a much longer, more gradual progression where you steadily improve, but have fun from day one. Mastering certain aspects of windsurfing can be challenging ie carve gybing. Having said that, as you progress in windsurfing, nothing quite gives the sensation of speed like a sailboard.
Wing Foiling has a much steeper learning curve and I know some people who have struggled for months just to get on foil. Albeit potentially because they were on the wrong gear or didn't have time to devote to learning in the right conditions. Learning winging on flat water is easy ish but the learning curve is steep and then tapers off. I find flat water wing foiling is more a relaxing than exciting sport and easy to get bored. Easy enough to change it up and start riding waves which is the same with windsurfing too.
Both are great sports, both fun but offer very different experiences. For exciting or thrilling sports, sailboarding and kiteboarding for the win. For fun and relaxing, wing foiling.
Just my 2c worth.
DM