Perhaps you can enlighten me, I've never used bar ends on any of my bikes, what's the advantage? Genuine question, not a dig.
No offence taken.
In my case, the main reason is to get a variation of hand position. If I stay on the flat bar for too long, then the fingers in my right hand go numb (it's just age I guess). The bar ends allow me to move to a position where my palms are vertical, so the radius and ulna (forearm bones) aren't crossed over; much like with drops but without the drop, if you get my drift.
I also find this a good position when climbing hills, I think because it brings my elbows in to the sides and gives me a better position for pulling up on the bars.
You might say, why not get drops? Well, in my case, I have quite bad osteo-arthritis in my left hip, so my knee won't come up as far as it used to. If I went down onto drops, I wouldn't be able to pedal without moving my knee out to the side, which would cause other problems. Apart from that, many people just prefer a more upright position, especially for commuting in traffic.