To start with, no I don't think that "Smart TVs" will be the future of computer games. All-in-one PCs have been available for a very long time and Laptop computers are essentially the same thing in a portable configuration. The screen-that-also-has-an-os model has been available for too long to call it the future of anything. I could, perhaps, imagine that Sony or Microsoft will build a screen into future units. There's no point in speculating if Nintendo will do that because, obviously, they already have. Reading your post though, it sounds like you have other concerns.
Perhaps this should be addressed by someone older and more knowledgeable than me but I've felt this was inevitable for a very long time. The primary benefit of video game consoles over general purpose computers in the 80s and 90s was their use of specialized hardware. The software industry, in general, was also smaller and less concerned with application portability. As a result, it made a lot of sense to have a special Nintendo specific console with games made, principally, in a Nintendo hardware specific way. Even by the early 2000s though, the benefits of specialized hardware were becoming less clear cut. The market was also larger and application portability was becoming a more important focus for commercial games. I was told, sometime around 2006 or 2007, by an employee of Telltale that it was simply impossible for a system exclusive game to make money. They're defunct so make of it what you will. Today, I think, it's increasingly clear that specially designed hardware for games is no longer particularly compelling. Microsoft's success has, somewhat, proven that out I think. Basically, I think that specialized game consoles are on the way out, if they aren't already dead, but consoles as a product probably aren't.
Well, I suppose this could happen but I think there are many reasons why "cloud gaming" is less than desirable. As long as the vast majority of games are not designed with the remote processing model in mind then I think it will have limited success. Also, I think, if this was a great model people would already be doing it with X11.
I think the main issues with this would be price and form factor. With some notable exceptions (i.e., the Nintendo Wii) video game consoles are sold at a subsidized price. The basic idea is that a hardware manufacturer will recoup the cost of the subsidy somewhere else. Maybe it's through Visual Studio licenses, maybe it's through selling an expensive developer kit, maybe it's through a sort of Nintendo Seal of Approval but at the end of the day it has to come from somewhere. I don't think it's reasonable to, for example, subsidize the additional cost of the monitor away. The types of computers that do get bundled in with "Smart TVs" are generally not going to run the kinds of games that the market is really interested in. These machines have the additional advantage of being much smaller and lighter than, let's say, a Sony Playstation. There are probably other issues too. The serviceability of the All-in-one comes to mind.
I don't see why it would sadden you that games aren't released on disks. Disks suck. They get scratched, they get greasy, they rot, and, if you're me, your little brother can put them in front of a radiator and let the heat warp the plastic. No one is lamenting the end of blowing on cartridges or punching in source code from a magazine line-by-line either. There's certainly something to be said for publishing media on some kind of durable ROM device but disks suck for this. They simply suck less than a number of other options and are pretty cheap to make. Either way, I don't think it follows that everything in the future will be a subscription service. That level of nickel-and-dime rent seeking is untenable. Regardless, you never really owned any of the games you bought. Unless you were buying SuperTuxKart all of those games came with a nice shrink wrap agreement saying exactly how you could use it and transfer it.
Is there something that you think is special about console hardware or disks? I haven't been a serious console gamer since 2011 and, honestly, I think I'm a lot better off for it. I'm sure I've missed a big title here or there but there are many, many more games I can play on my PC.