That's the packed size though, which is indeed pretty small. Unpacked is 540mb which is roughly the same as mingw-w64 which comes with MSYS2, just with added make/boost etc. Installation is (a bit) simpler than MSYS2 though, the possibility of just downloading/extracting/usbale is really nice. Though for actual longer term applications this could get annoying quickly with respect to updating (just downloading again?), installing additional packages (not possible?).