While there is wisdom in a lot of this, it's wisdom that is not unique to modular synthesis. There are more acoustic guitars collecting dust in closets than synths. Years ago, I worked in the MI business for a decade, and people constantly bought the wrong tool for what they were trying to achieve, so I get the point of this message. Here's the thing though, if you want to sound like Sonic Youth, Darkthrone, or My Bloody Valentine, you probably don't want to buy an acoustic guitar to learn on. Bang around on an electric, waste a lot of money on pedals and amps, and figure it out. You're not going to achieve that sound and workflow with a Martin D28. Similarly, if you want to make music like the YouTube generative coffee-mug-and-window-overlooking-a-peaceful-garden crowd, an MS20 isn't going to do that. Is that really the right instrument to start with, then? Man, I don't know.
People make amazing music by using instruments in the "wrong" way all the time. Just because you don't know what Boolean logic, half wave rectification, Euclidean rhythms, or even a VCA are right now, doesn't mean you shouldn't start the modular journey (you're going to have to learn about VCAs reeeeeeeaaaaaaaallllll quick, though). There is really no "right" way to use an instrument unless you are some purist gatekeeper. I worked around purists for years and they always sucked the joy right out of making music. They would scoff if you didn't pledge allegiance to some bulls**t Tubescreamer circuit from 1982 or didn't take the same musical journey they did. Ugh...
What is a way of life for some is just a hobby for others, and that's ok. I say the more, the merrier. There are enough good YouTube tutorials out there nowadays for people to make an informed decision about the kind of instrument they want to try out and learn (and maybe fail). I'd rather empower people to give synthesis a try than suggest they are only attracted to the pretty lights and graphics. Sure, aesthetics make a difference for some (there are glittery finish guitars and drums for a reason), but aspiring musicians deserve more credit than just being bandwagon-hopping squirrels. Most people are savvy enough to understand that you don't become Eddie Van Halen, Aphex Twin, Neil Peart, or Brian Eno overnight just because you bought an instrument.
Yes, in the modular world mistakes are very expensive. Also, mistakes lead to new avenues of thought and creativity. Synthesis can be frustrating, but so can learning and becoming proficient in violin, drums, melodica, djembe, or 8-string guitar. There are growing pains with every instrument and technology.
Maybe you don't NEED a modular synth. Maybe you just WANT a modular synth. That's fine. I hope you dedicate some time to it, have fun, and make some cool music with it.