I don't want to spend $99/year for the rest of eternity for the privilege of having a slightly less scary warning when my users run my app for the first time. Thus, the readme for the one macOS app I made that has gained a bit of popularity instructs users to right-click, then select "open". Works reasonably well so far.
I would absolutely have embraced notarization if it was offered for free. Otherwise it feels like straight up extortion.