A FIS will not tell you if you are lost
Oh yes, they will.
UK version: As you're passing through your busy airport's of choice controlled airspace, your squawk will tell the local controller who you're on the radio with, as a result of which your friendly FIS controller will make you aware of the fact that you might not be exactly where you thought you were. Of course first you will have gone through a bit of airspace where you were perhaps not entirely welcome, but that's not the point of this discussion
Elsewhere, a FIS is for all purposes what the UK for some reason calls an RAS, and they'll bark instructions at you as needed to keep everyone happy.
you should be careful writing stuff like that on a public forum if you do not have a good understanding of what you are saying.
I do agree with that, but more than what's being written, in my opinion the onus is on the reader to critically analyse any information he might get from here. You get what you pay for and all that.