QRSS needs low power
I regularly visit the WSPR Old Database, to look for stations that use very low power. It is striking, every time, that almost all stations use much power. Because WSPR is QRSS, the power of the WSPR station can be as low as 10 mW. With a power of 10 mW your signal will only be spotted, when the propagation is good.
Many stations use 5 watts or 200 milliwatts, which is way to much, because of clutter spots that will be fill the band, when the propagation is poor.
Many operators believe, probably due to unfamiliarity with QRSS, that 5 watts is always QRP. But of course, that is not the case.