Why are so many people spending so much money to build “perfect” streaming system?

I have a decent system that I’ve built (and rebuilt) over years and am happy with the sound. Via trial and error the streaming aspect has evolved to a streamer-only device and a DAC, both relatively low-cost (iFi for both, but I also found that a Topping E50 would do a great job; BTW, I’d definitely choose ethernet over wifi). By separating the two I got a streamer with a wide range of service compatibility, and the ability to try different DACs to optimize the analog signal for the rest of my setup (always using a USB DAC for widest range). I’m using Qobuz but not paying the full price (every Black Friday season you can get a better deal on an annual subscription), and I decided to purchase Roon (figuring I’ll live long enough to realize the financial discount of ownership) because it’s the closest thing I can get, right now, to the database system I’d write, myself (I feel it pays for itself in the tree-related connections to artists and music I’d never have heard of, otherwise, as well as its recognition of sub-genres and its hardware optimization and zone coverage). And that’s the "budget way" I’m doing it.

Of course, the benefits are relative to how much you enjoy music; my preference is for having a system I like that can withstand the test of time, and doesn’t come between me and the music/performance. I’ve got what would appear to be an expensive system (other than the streamer & dac) - I grew it because of the sound and design philosophy, not because of any bragging rights - but have paid relatively little because I’ve been patient. If you’re in the last half of your life, I’d suggest you give it a try; it doesn’t have to cost a small fortune.

howsoever, as per @lanx0003there are diminishing returns in this game and, purely subjectively, the wiim is the (dirt cheap) point at which sonic improvements become more marginal. just my opinion.

No question that there are diminishing returns with regard to audio (Or just about anything for that matter).  Determining what this point is will vary on an individual basis. Each one of us has their own level set points of performance/value ratio.
 

I was pointing out that some would make the case that the Wiim is  “bit perfect” and thus cannot be bettered. Anything purportedly better is wasteful spending and there’s nothing to be gained sonically.

Charles

Back to the question of why are people spending money (or "so much money" in the words of the OP) on streaming. I suppose the question is, relative to what, in the sense of why do people spend lots of money on anything? But to avoid going down that wormhole, let's just confine the question to spending on streaming versus spending on other source components. To that extent, I'd suggest that people are spending money in order to get an improvement in the quality of reproduction - probably with reference to other analogue and digital sources they own. In my own experience, whether it's CD, Vinyl or digital delivered over ethernet there is huge scope for improvement and, unfortunately, it usually costs money. In my own experience, streamed music is just as susceptible to improvement as CD or Vinyl.

I've built a number of systems over the years, I'm not an equipment churner, rather system builder, so the following pattern repeated itself over the years. A series of upgrades resulting in marginal gains until system was completed. I considered a system completed when only minor tweaks left. I considered new speakers or amp to be the beginning of new system. So this pattern repeats itself a number of times over period of over twenty years.

Each successive build relies upon knowledge gained from building past systems, so marginal gains also experienced from one system to next, this means each successive system better SQ than previous systems.

So we come to present system, same pattern followed with far more attention paid to streaming setup vs. prior system where I first incorporated streaming into setup. The vast majority of changes I've made over past five years with this system have been streaming related which has resulted in the usual pattern of marginal gains.  However with this system and more recent changes in streaming equipment there has been this breakthrough or surpassing of this certain plateau that has always existed for me with digital in general. The one purchase that took me over that plateau was my new custom build streamer with amazing LPS. Digital that now competes with the best vinyl setups I've heard in regard to ease, refinement, harmonic development was made possible by this single purchase. Certainly, all the marginal gains made by all the changes made prior made it possible, but the streamer made all the difference.

So, based on my experience obviously I'm going to judge streamer as the most important component in a streaming setup. Assuming one has a system capable of extracting max potential from a streamer, the streamer has become as important as amps and speakers  in my calculations.

The one purchase that took me over that plateau was my new custom build streamer with amazing LPS. @sns 

Is it raspberry pi based?  Could you articulate and share a bit more details with us?  More importantly, I am interested to know how is it compared to the streamers you have owned before.