To be clear, Sony isn't in the 'Smart TV' business. They are in the TV business. Roku, by comparison, is in the 'Streaming Appliance' business. It's really about all they do. They make network connected media players. On the residential side, this is Roku. On the commercial side, they do Brightsign (the color will look familiar). This is their life and their livelihood.
So, when the Sony player has a weak control panel, or ARC doesn't quite work right, or an app no longer works on the TV... Sony really doesn't care. Denon has had similar issues with things like Pandora failing on their A/V receivers. They fix it... eventually. But, this is not what these companies are in the business to do, and expecting, let alone demanding, high performance streaming from a TV company will make people very sad at the end of the day. If you don't believe me, just read the negative reviews of these products and find out how many people do NOTHING but complain about the 'smart' features. It's insane.
Roku, for $50-$100 can solve all of that.
All this said, you may find this post goes on for several more days and a bunch more postings before you go out and buy a $5 toslink cable and hook it up and have your audio issue fixed in 30 seconds.
ARC is great... when it works. But the number of people who complain about it not working is ridiculous. This is because of how poorly HDMI implemented this feature into their equipment. ARC should just be a selectable source on your A/V receiver. CD, Cable, Game, ARC, Blu-ray. It should NOT be a part of HDMI-CEC. This would mean that you manually select it and the TV, if it is on ANY input that is not the ARC input, should be pushing audio out of the ARC connection. But, in their infinite wisdom, HDMI did not implement it this way and you are stuck with what may or may not work. Not your fault, but not an ideal situation in any way.