Or buy one with more ports?
Just need to find one.
It depends a lot on what you want to use it for, but even one that has USB3.2 (or 3.1G2) for the 'upstream' connection, with an SSD inside, you're going to be getting pretty average performance once you start pushing beyond 3 or 4 USB ports.
I've seen three of this type of thing - this Hagibis one plus a knockoff that looks very similar but has no brand - also 2x USB2, 2xUSB3, SATA, Card Reader; and the Satechi, which is 3x USB3 type-A and 1x USB3 type-C, plus Card Reader.
It turns out there are a bunch of companies all selling a product that could essentially be described as "a Mac mini sized stackable USB-C hub with 2x USB3 ports, and some other assortment of ports, often 2x USB2 and card reader".
You can boost working experience on your Mac Mini with the USB C Mac Mini dock or docking stations. See the best Mac Mini docking stations.
mashtips.com
There's just one on that page that is even vaguely "Mac mini size" that isn't essentially the same thing, and that's the Dockteck one which has ethernet and video etc - but still only 3x USB3 ports.
Believe me, I understand your point of view. The mini + stackable accessories would be a pretty cool setup - but for some reason accessory makers aren't really jumping to capitalise on it.
