My TV remote doesn't control my AV amp, my Apple TV, my Sky box etc. My Sky remote can't control anything but itself. The Apple TV remote can't control everything. So there still is a place for a Harmony remote. Even without my hifi etc it would still be used as it's the only product which can control everything including all the various functions.Extremely niche usage requirements which 99.9% of people will never have.
I can play music, control TV and amp all off the one remote but that's because I use YouTube music subscription Vs CDs and Don't have a seperate hifi amp.
I'm happy for you and your TV remote, but just because you can't see a use for a product doesn't mean it's useless.