There are plenty of "good" SD cards that are not SLC. I use a multitude of SD cards between devices ranging from multiple Pi's and other SBCs to mobile devices to 3D printers to cameras, they're all name brand but I doubt many if any of them are SLC. I think I can count the number of failed SD cards I've experienced on a couple of fingers.
Sure, spec SLC if you have a mission critical application. If you're just doing something at home, take a backup image occasionally and have spare cards on hand for when one fails, and just about any brand card that isn't fake and meets its specs will likely do just fine.