A bolt is either fastened or it isn’t. If the wire is all that’s left to hold it, then it isn’t fastened and your parts are being held together with a very weak piece of wire.
You're much better off with a loose bolt, than a missing one. It'll hopefully make itself known somehow (maybe even just visual inspection) while still remaining somewhat attached, which is better than nothing.
When I searched for images of wired bolts just now I saw many examples where the wire is done up quite tightly, which doesn’t seem right.
If the painted seal is broken or misaligned, you know the nut has moved.
https://fastenerengineering.com/what-is-a-castellated-nut-an...
There's different kinds of bolts that get wired, with different kinds of goals and results.
My only experience is wiring bolts according to the rules for club racing motorcycles.
Some things, like oil sump drain bolts for example, wiring them will stop them backing out so far as to fall our, and while it will probably weep oil if it loosened enough to take ups the writing slack, it wouldn't dump all the oil out quickly.
Other things, like axle bolts, if it backs out enough to take up the wire slack, it'll have lost its clamping pressure and that's bad, but not immediately catastrophic. The major axle loads are all in shear so the wheel won't fall off, it'll just get more floppy than it's supposed to be. Long term it'd be bad and cause wear to the point that something would eventually fail, but it'd get you to the end of the race most likely, and hopefully the rider will have felt something odd and gone looking or a post race inspection would have caught it.