I use foundation like a concealer, i.e covering blemishes and uneven skin. Other than that my skin is bare. Concealer is too thick for my sensitive skin, it literally feels heavy and like my skin is suffocating. Even with foundation I can only use lightweight ones.
Check what your products are based on. For oily skin, surprisingly, oil/silicone based products hold best (though they induce acne). Water based products can crack and appear blotchy if the skin is oily enough. This is doubly so if you use products that are based on different consistencies. Say, if your foundation is water based, but your primer and moisturiser are oil/silicone based, it’s gonna look bad, and vice versa, and even if the primer and moisturiser are different bases.