A stupid question for which there's no sensible answer.

For me, the question is the building process leading to a satisfactory system based upon individual choices and external factors.  After much research and years of listening, I found myself in the position of having the means and time to create what for me was / is a system where I am no longer chasing the last 0.05 percent.

Financial considerations create a range for most all of us.  The next important part is the WAF factor in terms of what our system will do to the living area.  The dedicated listening room is not the norm for most people.

I found that the speaker drove the amplifier choice.  I went through a few amps before finding my keeper.  Source is important, but I agree that room treatments have more effect on the sound.  I would argue that quality source material is as important as the source playing it.

I have found that other tweaks are really at the margin to my ears, useful, but nothing to break the bank over.   I do have dedicated power circuits due to the requirements of my amp, but also have an 86 much TV in the room that does impact the sound a small bit, but keeps peace on n the family.  
Everyone has a different journey, I have found mine to be very pleasing sinceI quit changing gear all the time.  Now it is all about listening to the music.

This is not a dumb question at all but i can say that it is the whole system of everything that is the upgrade making sure that every part and parcel works together.

Recording, speakers, room, equalization, and given the quality of today's cheapest electronics and cables, as long as you have proper wattage and resistance, nothing else.

Of course the room impacts the sound quality most @mahgister. That’s a given. My cousin has a basic system in a converted warehouse with extremely high ceilings and a concrete floor. The room is completely open, slightly rectangular and must be 2500-5000 square feet. His system sounds amazing with NO treatments since none are needed. I think his system is under $2K or so with turntable, receiver and speakers. Biggest % in his turntable (used Rega P5 with mid Grado cartridge).
That’s why I mentioned the Linn paper and the source being most important - for him it is. the room treatments can’t fix a terrible room.

the room treatments can’t fix a terrible room.

Yes you are right if someone dont have a room to fix....The source is important, but then the vibrations and the electrical grid noise floor are on par with the source quality and these 2 are also way underestimated in their destructive S.Q. power...Source is important but source is part of a complex problem... This is my point... And few make it in audio thread...

For the room problem, any room can be fix if mine can, a 13x13x8feet1/2 irregular room where one speaker big box is in a corner the other not....With 2 windows...

There is more ways to fix acoustic of a room that there is a number of materials solutions proposed and sold by acoustic retailers...We also must add to the passive treatment and work with active one (non electronic one in my case) ordinary resonators of different size, conventional Helmholtz bottles, non conventional Helmholtz tubes and pipes, Shumann generators grid, ionizer(non ozone one) and a few others....Acoustic retailer dont propose that much... But it is the tools with which we can deal with bass and very high frequencies problems in a difficult room... And there is plenty others i did not bother to try and which are very powerful ... Then....

I bought nothing for that job except peanuts costs products , i did it myself, with results so astounding that my system bear no resemblance at all with before and after....If i can do it myself, a non crafty hand reader of books, anybody can.... Trust in your ears and experiments is the way....Trust in our own ears are not recommended by techno fad ....But a room is created for ONLY your particularly designed ears not for a crowd...We must then use these ears we own first and all along.... The results will sound natural FOR our ears....The goal is the vibraphone and piano sound must be distinctly perceived in their own space with a distinct timbral tone and his aural varying colors and hues with his decreasing decay all that filling the room 3-d and not coming from the speakers.... When you reach that you dont speculate about a source change or an upgrade....

A bad room does not exist for creative mind, only difficult one...Those who said the opposite sells ready made generic acoustical solutions and dont want to waste too much time on difficult room...Paying an acoustician will do but will be costly if the room is difficult to tame....

All small room exhibit very different geometry , very different topology (doors, windows, and openings space) and very different materials content (with different acoustical properties of absorption, diffusion or reflection unbalanced) all that ask for specific acoustical controls not only passive materials treatment.... A small "bad" room is not a vast theater where acoustic law are simpler to apply in a linear way....

I am conscious that what i propose cannot be deal so easily with in a common room or a living room...That is the big problem... And i can only say that this illustrated my final point, more than source, a dedicated treated and controlled room is the main center of audiophile search.... Not the choice of a dac or of an amplifier.... Blind upgrade consumerism motivated by unsatisfaction is not the way.... Most good audio system can deliver very high S.Q. unbeknownst to their owner because they never listen to them in their optimal working controlled dimensions, what i called their embeddings...

Audiophile experience dont cost money at all, it cost thinking ears, and a room to set..... I proved for myself that the materials cost peanuts.... My room is absolutely not perfect and perhaps not even optimal.... But listening music i think that my room IS perfect....It is not a a deceptive illusion if you listen the piano like a real piano.... I dont wanted perfection to begins with, only good musical experience.... Thats all....