That's true. However who is next in line for sound quality?
The sound quality of your system is largely determined by your speakers, and how they are set up and voiced to the room.
Most of a budget should be speakers, which you need to select carefully. The vast majority of speakers have significant defects. So you have to choose speakers very carefully. Gene mentioned in a recent video that people should choose their for ever speakers. I could not agree more. There is enough known now as to what will make a speaker sound good. The problem is the correct data is seldom available.
When it comes to electronics, what you really want is reliability and therefore longevity. That is why I strongly recommend external power amplification. Again you should be able with care to select your for ever amps.
Then you get to the front end. Peripherals also need selecting with care and the preamp. However AV in the home is not quite 20 years on. So this technology has been immature and evolving. I now feel it is reaching maturity. I think screen resolutions are as good as they need to be. Unless we get 3D from some spectacular advance video quality with a screen like your LG C class is as good as it needs to be. In domestic situations I think we have enough, and may be more than enough channels.
So we are approaching the time when pre/pros are also as good as they need to be, but some small evolutions will likely take place.
What I'm saying is that the current systems we are using are now close to maxed out.
So improvements now will require a change of practice. That change in practice will be active speakers with DSP for perfect time alignment. Likely connection will be Ethernet based rather than speaker wire. If latency and some other issues are solved, then connections could well be Wi-Fi.
I suspect many think I have spent a fortune on gear over the years, well I have not when you consider annual yearly budget, over almost seventy years now. What I have done, is bought for the long haul. I'm still using gear I have had for over 60 years. I have speakers in my system I designed and built 40 or more years ago, and they are still very good speakers. All the speakers in my system are for ever speakers.
What has changed are the front ends, in the last 15 to 20 years, as we have moved from a mature two channel audio world, to an evolving multichannel AV world.
So my advice to you is to concentrate on forever gear. Having to upgrade for reasons other than true evolution of standards, and maturing technology is costly in the long term.
So I would seriously look at forever amps. I would keep to no more then two amps in each case. So for instance, a good foundation in the electronics might be a 19" rack of QSC amps. They have a reputation of being built like a battleship.
For the front end I would recommend either a Marantz or Yamaha pre/pro. I have used Marantz, and been very pleased with them. They sound excellent. When it comes to electronics, you want to focus on build quality. Failures are a PITA and expensive. A failed unit has an SQ of zero.
Lastly make sure you have appropriate protection.
The bottom line is once you have your forever speakers, it is reliability you need to obsess about. In addition that will sort your SQ issues, as reliability is strongly associated with elegance of design, and that goes hand in hand with superior SQ.