What makes you build a system around an amplifier?

My system is built around my speakers which is the way it should be.

I don't get the concept of building 'around' a specific component..

We all have some sort of starting system that usually is assembled by a combination of what we can afford at the time, what advice we get from friends and magazines and what we happen across in the local marketplace.

After that we upgrade, sometimes haphazardly, sometimes because a piece of equipment we covet shows up at the right price, or because something in the system breaks down and needs replacing.  I don't have any audiophile friends that scrapped their whole system and started anew.

Sometimes one perceives that the front end needs an update, sometimes the speakers and sometimes the amplification - there is no rule nor commonest route, at least that I have noticed.

I don't even remember what order I upgraded in over the years, but I have equipment that has been in one or another of my systems since the late 1980s as well as systems with new (to me) speakers and amplification, but front ends that have been with me for some years.

I guess that I have to disagree with your premise - that people more often upgrade in any one manner.

Building a system around an amplifier or around speakers is so old school. The trend these days, and I'm just going by what I read here, is to build a system around fuses.

After reading all of this, "What makes you build a system around an amplifier?". For me, it is a very well-matched speaker. No matter how good an amp, they all don't play well with all speakers. Synergy is most important, not a certain amp manufacturer. How well an amp/preamp or integrated amp and a speaker work together is very critical. Get this wrong and you most likely will never be happy. IMO and YMMV of course.

My system is built around my speakers which is the way it should be.

I agree. Especially if the primary consideration is monetary value. In other words, I'm of the opinion that whatever it is the system is "built around", it should clearly be the most expensive piece. Typically, that is the speakers.