They don't seem to be. HackRF is 1MHz - 6GHz and it's a beast (you can go lower with upconverter like Ham It Up). I only just learned about KiwiSDR and I'd love to know for which use cases people would choose it over HackRF. If I understand correctly the setup may be easier, but other than that?
I'm totally with you. The selling point of KiwiSDR seems to be that it allows everyone to use the same device simultaneously as the entire spectrum that KiwiSDR can capture is available all at once.