If everyone knew this cheat sheet there would be no skincare market at all:

Hormonal acne = caused by lifestyle and genetics. Solve with lifestyle changes and/or medication and supplements

Any kind of texture issue = caused by skincare and make-up clogging you, improper cleansing. Solve by reducing products and introducing a retinoid

Acne in general = caused by either products, hormones or both. See first point + introduce a retinoid

You could literally whittle down the skincare industry to 20 total brands and not much value would be lost. Who would be in your 20 brands?