Maybe I'm a bit of a downer there, but I looked at the overall effort and time investment of making Gridfinity and rather got myself a cutting board and glue to recycle old cardboard.
Don't get me wrong, Gridfinity looks amazing. But, cutting a few cardboard base plates from old shipping boxes into place and putting together little stands for a metronome, tuner and a few other small things, as well as a bunch of boxes for plecs and other small stuff took like half an hour to an hour.
And I could reuse some trash shipping boxes I had around here.
I needed to organize a bunch of tools and other miscellaneous items in a closet. I tried printing a few Gridfinity items, but quickly realized that it wasn't worth the time, effort and filament + electricity costs. I ended up going to the dollar store and buying a bunch of plastic containers and some labels, and managed to get everything organized in an hour and for under $10.
I think Gridfinity is more geared toward people looking for a hobby than a practical storage solution. Which it totally fine - people are definitely creating some cool stuff with Gridfinity - but probably good to decide up front which group you fall into.
You'd be surprised how many ways there are to make storage containers. Gridfinity is one of them.
Along these lines, foam core board is a super common and effective material for making drawer organizers and little boxes. It's very cheap and holds together surprisingly well with hot glue or super glue. Adam Savage is a huge fan of it and he's tried everything.