When mom cooked breakfast, she'd collect bacon grease (as, like, supplemental butter) and add that to subsequent meals. AFAIK, it still happens, but is probably less common.
I know it's bad for me, so I use it very sparingly, but I have a jar of bacon grease that gets used every so often. I'll be honest, I don't know anyone outside my family that still does it.
I'm also from bumfuck nowhere, so that could be an influencing factor on why I am the way I am.
You must do a ton of bacon because I can only at most use the leftover fat from doing some pork (bacon very rarely) in a frying pan to, immediately afterwards, sauté some vegetables or such on that fat.
I don’t use it sparingly and I also have a jar of bacon grease.
The day I learned to put a coffee filter or paper towel in the jar under the lid ring to filter the hot oil? Game changer.
My grocery store carries “bulk bacon” which is packs of low quality fatty bacon that’s great for cooking. I buy that sometimes and the grease off a pound fills a pint jar about halfway, sometimes more.
Cooking for two people, I do half a pound of thick cut bacon, and when it's done and the bacon off to the side, put in 6 eggs scrambled up right into the grease. I've found this is the perfect ratio of bacon grease to eggs.
Bacon grease has a higher smoke point, a longer shelf life, and makes veggies taste amazing. It's also high in saturated fat and sodium, but ya don't need much of it - often just a knife tip's worth. The only time we buy bacon is when we run out of bacon grease for cooking, maybe 3 times a year.