I have never suffered from Audiophilia Nervosa so I have kept my gear for decades.
My first system, bought in my (graduate) student days in the 1970's by working in a bookstore:
Quad ELS 57, Quad 33/303/fm 3 electronics and Linn Sondek LP 12/SME 3009ii/Shure V15iii
In the early 1980's my parents gave me a first generation Philips cd player that I replaced by a Marantz multi format dvd player twenty years later and that I replaced in turn some years later by a Panasonic Bluray player to work with the new Plasma screen.
A bit later, and when we were living in a much larger house, I replaced the old Quad stats with the current 2805s.
The Quad 303 proved a bit weak to drive these less efficient speakers in the much larger room, so I bought a refurbished Quad 606-2. I also added a B&W PV1d subwoofer, and soon after added an Antimode 8033 to tame it.
In recent years streaming via the Chromecast Audio had become our primary source, so this year I finally bit the bullet and replaced the old Quad 33 preamp with an RME ADI-2 DAC. The fm tuner has now also been retired and was replaced by internet radio. The family would not let me sell the turntable, so I bought a Pro-ject Optibox E phono preamp and ADC to connect it digitally to the DAC/Preamp. Vinyl purists may be horrified, but the sound is pretty decent (better than into the Quad 33
).
So the pattern has largely been to follow developments in sources, an update of the speakers before they would fail, and more power (plus a sub) to match the much bigger room.
I still have the old ELS 57, Q33/303/fm3 system. Recently I had to get it out of storage when my new Quad 2805s had developed an issue (something with the wrong glue having been used at the time). So while those were being repaired, I listened to the old system. I could still very happily live with it.
And yes, this has been pretty expensive gear, but amortized over such a long period it was not too bad. I know may people who have spent more per annum for less listening pleasure.