Grantmac said..
All forms of kiting have the worst self-rescue when the wind really dies, but as others have said kite-foiling places people in the position of most likely swimming a long way.
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I don't think that is accurate or particularly relevant. There are many effective and efficient ways to self rescue with an inflatable kite. Even ram air kites can be self rescued quite effectively in most cases. In it's best form sailing a downed kite is almost as much fun as sailing a small dinghy.

Ultimately you need to be prepared to sacrifice equipment if you need to do that to protect yourself.
More importantly, any form of wind sport device can get into a situation where things go from good to bad with little warning. Just the other day I got bucked off a foil doing nothing in particular and that ended in 3 minute drama that could have had bad consequences.
I think the "just paddle in" idea is hugely over simplified. I am very fit and very experienced but having paddled in from a couple of km out, it is much easier said than done. It takes ages. It's tiring. It's hard. (According to my GPS the kneeling "lifesaver" paddle was easiest and fastest.) It happened a lot until I simply accepted that wing foiling is a strong wind sport. I am working on the techniques and gear for lighter wind wing foiling. I am hesitant to go down the route of buying huge foil wings. I have more than enough wing gear already.
Given that many wing foilers are less than athletic, you really need to practice paddling and self rescue techniques before you need to do it. You need to ride in a way where your escape route is assured the whole time. It's not a good idea to ride a couple of km out to sea with no plan to get back when things go wrong.
Wing foiling has several distinct issues to deal with.
Number one is that you have much less power at your disposal. You're much more vulnerable to minor drops in the wind. Power and speed lets you glide through all sorts of wind fluctuations.
The rider is an inherent part of the structure. If the rider is damaged or tired then you've got nothing. A kite can launch itself and drag you back to shore. Even a damaged kite on the surface will tow you in. Body dragging a sailboard is doable. You can body drag a wing, or sit sail or variations on that. I guess you could rig the leashes to support the wing to sail in if you're damaged.
The wing, rider and board are all tied together with leashes. Virtually every session has some kind of "micro-bump" where the board hits you or you fall into the wing, or the wind tries to impale itself on the foil. All it takes is some bad luck and you could be injured and unable to use the wing to power your way back to the beach.