Hm, shouldn't we avoid doing the escaping in the first place?

That was my first reflex, but turns out it makes it overall easier to create workspaces you are locked out of.
Invoked edge case for the escaping is using a workspace called "1" (double-quotes part of the display name). That's arguably just asking for trouble, but once it's in there, we need some way to make the name precisely round-trip

As of now, sway IPC-side lets you do that by putting problematic characters individually between single-quotes, if the first character in the argument is single-quoted.
This is not compatible with i3, which will not interpret the single-quoting, and will interpret ' \ ' shell-style

Possibly relevant (also issue with quoting \):
#5931