I have frequently used tone controls in the past right up until a week ago*.
I have used them to ease off treble and bass a notch (Arcam Solo-Mini + Rega R3s), I have used the loudness button (when any of my amps had one) for listening at very low volumes late at night.
*Until a week ago I was using some mild EQ on iTunes to boost upper bass a tiny bit with my old Naim n-SAT speakers.
I have never used tone controls 'to the max' as you describe and never used 'loudness' at anything but low volumes. I doubt I have ever used treble or bass more than +/- 2 notches out of 10 (if they had been scaled to 10).
They are useful to compensate when changing between speakers (or rooms) or - very occasionally - with a really 'rough' recording as a viable option to not playing it at all.
If the options are either (a) keep a favoured system the way it is with a little judicious 'adjustment' or (b) spend lots of money and time tweaking the tonal balance with new amps/speakers/sources/cables etc. then I would go for (a).
I happen to have kit without tone controls, and this has been true for about half of the last 30 years on and off. I do miss them and - ideally - I would like to see subtle and well designed tone controls on all amplifiers. I would like to see companies like Audiolab re-introduce tone controls (as they had on the original 8000a from the 1980s).
Companies like Luxman, Accuphase, Quad, Yamaha, McIntosh, Arcam, Rotel, NAD... and many others still include them at all levels from the esoteric to the humble. But there is a 'hair-shirt' element of manufacturers who won't.
Despite my liking for tone controls (I even love backlit VU meters despite their uselessness) I could never use tone controls 'to the max' as you do. I have heard (all too often) what it can do to the sound.
Someone else mentioned wine. I would also draw the parallel with seasoning food. Some people will put huge amounts of salt and pepper and ketchup (and sugar) in and on everything. Some will taste the food first then 'adjust' with a little seasoning. Some will not season food at all (even when cooking), believing that ingredients should only taste of what they are without 'aldulteration'.