Agreed with what everybody has been saying about modular cost vs other instrument and equipment costs. And about how flexible it is.
I’m also a Max and PD fan, and use both for a lot of things in both music and art. I’ll echo some of the previous statements made about immediacy and planning. I find physical modular (and similar things) more appealing when I want to turn something on and just try stuff. Max or PD feel like they require more planning, and more steps before something meaningful happens… you could get around that by building up your own library of higher level patches, but in all my years using the tools I’ve just never felt like doing that.
As for modular size, I think I have a fairly big system (by some standards anyway, on MW i think my qualifies as “tiny”). After a lot of experimentation I’ve landed at a stable size of 12U (4 rows) 104hp. But unlike @ellips_s, I find this size works for me. It’s organized more or less as one row of sequencing, one row of modulation, one row that is two synth voices, and a row of sampler/drums/effects. I also use a few non-eurorack things on a regular basis.
Sometimes it still feels like too much, but I use it all and really love what I have.
Was it expensive by the time it got to this point? Sure. But no more than other good instruments, studio equipment, furniture, or other tools for my work and art. And it’s very satisfying.