I’m an unabashed loud listener, so this desire seems very foreign to me haha. But yes, as has already been speculated, increasingly exotic gear is not the solution - some from of EQ or a good "loudness" mode is probably the way to go.
You’ve hit on an interesting audiophile trope / anti-patten: "this system is so good (i.e. expensive) that you get full detail and dynamics even at low volumes!". I would posit that such a system (or component) is specifically optimized for low level listening, and would in fact sound quite unbalanced (too much bass and/or treble) when pushed into higher volumes. I am sure MY system sounds quite dull to low volume listeners!