no end user knows what privacy guarantees they are getting in a specific lightning transaction.
and if you dont know, or can't know,
its a problem from a privacy perspective.
Discussion
Why is it unknown?
because it depends on case-by-case circumstances outside of the user's control
the path finding algorithms are definitely too voodoo but in fact most payment paths are longer than 3 hops which still is better than signal timing
at least you are recognising that it uses onion routing, unlike most of your fellow privacy cultists
onion routing that is still unsupported by the biggest implementation and only really works under laboratory conditions.