Are soundbars and home theatre systems becoming more similar?

My Samsung Q 990b soundbar is currently linked to my living room TV after I recently bought it. Its sound quality and impact on Dolby Atmos scenarios are both quite impressive. I have a complete home theatre setup with a Marantz AV Receiver (5.1.2) and a Q Acoustics speaker package in a dedicated room. When I compare the sound quality of an actual home theatre system to a soundbar, I find that the soundbar often outperforms a real home theatre system in many instances. I'm not sure if there is a problem with my home theatre system or if soundbars have advanced enough to finally displace large home theatre systems.