Cascadea is a decent Stylus stand-in for Safari, though it isn't free (currently costs US$2.99).

Been a Safari user for years and still consider Apple doing anything to lose uBlock support one of their worst moves in that space. My browsing honestly feels so less safe without uBlock Origin, almost never had a dodgy popup or banner do something weird that wasn't blocked but once you're in the much weaker Safari only blocker ecosystem it happens constantly.