Combination skin gets treated as a mild case of oily skin, and over 50 that is exactly backwards. What you have is a T-zone that still produces oil and cheeks that have stopped, and a product chosen for either half makes the other half worse.
Why it gets worse with age rather than better. Sebum production falls with age, but it does not fall evenly — the forehead, nose and chin have the highest density of sebaceous glands on the face and they keep working longest, while the cheeks and the area around the eyes dry out first. So the gap between your oiliest and driest skin can widen in your fifties and sixties even as the overall oil level drops. Combination skin at 30 and combination skin at 60 are not the same condition.
The matte trap. Someone with a shiny nose buys a mattifying foundation, and it works on the nose. On the cheeks, the same oil-absorbing powders and film formers have nothing to absorb, so they pull at what moisture is there and the base goes flat, tight and patchy by midday — and settles into every line it can find. This is the single most common reason people over 50 decide foundation does not work on them. The comparison is laid out on mattifying vs hydrating primer for mature skin.
The hydrating trap, which is the same mistake in the other direction. A rich, dewy, luminous base makes dry cheeks look wonderful and turns an oily T-zone into a slick by lunchtime, taking the foundation with it when it slides.
Which leaves a narrow target. What actually works is a base with a natural or satin finish — neither matte nor dewy — at light-to-medium coverage, applied thinly, with the zone management done by a separate step rather than by the foundation. That separate step is primer on the T-zone only, powder on the T-zone only, or both, and it is covered in the section below.
One honest note on the alternative. Some people are better served by using two products: a dewy base on the cheeks and a powder base on the nose and chin. It works. It is also twice the handling and twice the shade matching, which is a real cost if your hands are sore or your eyes are not what they were. Every pick here is chosen so you do not have to do that.