Are audiophile products designed to initially impress then fatigue to make you upgrade?

No. Every manufacturer makes what they think you'll like based on their observations of you (the public). Every now and then some do it better than others, some even much better, but it's not a conspiracy.

All the best,
Nonoise

....what exactly is the purpose of this thread ? 

@johnk  There could be another reason we tend to be constantly rebuilding and tweaking our systems.  Studies have shown that Endorphins are released in our brains when we spend money.  Just like Pavlov's dogs, we are conditioned to the hit of pleasure we get from buying things.  In fact, studies show that more Endorphins are released during the planning process than the actual purchase.  And, purchasing items that have a long delivery date keeps the buzz going.  Sure we can convince ourselves that changing our interconnects or buying that new power cables is justified by the improvement in sound, but maybe we all need to look in the mirror and accept the fact, we're junkies!!!  We should all be pointed to the nearest 12 step program. 🤣  But seriously, there's something to be said for this.   

If something is fatiguing, it is likely the room.

Not true look at very high end dacs like the chord Dave 

It’s  very detailed and cutting edge but very neutral ,which for instance if you have a Vacuum tube amplifier or preamp would be a ideal match , also with the hundreds of brand Audio cables ,even digital they all have a solid signature that you personally can Taylor to your specific Audio system ,it just takes time and monies to 

match, sometimes you have to sell something to get better synergy ,but that’s what Audiophiles do. Some Audio dealers allow a trial period . You control your $$ .

you absolutely should research every product and reviews,forum information you are considering to purchase.