'I use Griot's Leather 3-in-1. It doesn't leave a greasy film and offers UV protection'
Me too, and prior to that with earlier cars I used Griot's Leather Care. Every leather car I've had has had the coated leather, but even so they benefitted from the Griot's. How I do it is, I vacuum the inside of the car using a soft brush attachment on the upholstery and dashboard (instruments, vents, etc.) I might take a damp wash cloth and wipe the seats/any other areas I think need it. Now I take a sponge made for the purpose or a folded wash cloth and start applying the '3-in-1' to the leather trim. I like doing this early on a hot day so I can close up the car afterward and let it bake in. I do not buff it because when you get through it simply looks new, and it was not shiny then. Another great thing about Griot's is it has a leather smell that sticks around. I might do this twice a year.
As for the odd-looking spot on your seat, I don't know what it is but it isn't 'wear'. I don't even know how you would put wear on a seat in that spot. Griot's may help or not, but it won't hurt. I use it on the steering wheel and gear knob too because it has no silicone or anything slippery. If you get a scratch on the steering wheel which is fairly common, repeated use of 3-in-1 on it will seal it up and it will be hard to find.
On my '03 Saturn VUE with beige leather trim, all the interior looked as good when I traded it in in '11 as it did new except the driver's seat, which had creases from use but was still supple and with no cracking.
I've been using it on my wife's '15 Honda Odyssey since new and the seats are still perfect. Drivers seat is getting the expected creases/wrinkles but this is what gives a leather interior its charm. For the people who use nothing or inferior products, those wrinkles become cracks and the leather feels brittle - because it is.
2017 Sportage SX AWD