The reason most products fail you is simple:
they are designed to hide aging, not address it.
Most high-street "instant smoothing" serums are packed with Silicones.
Think of them like a layer of spackle on a wall; they fill in the cracks temporarily so your skin looks smooth for a few hours. But once you wash your face, the dullness and lines are still there.
Even worse, that heavy film can block your skin from breathing, leaving it even more dehydrated. You're paying for a temporary fix, while dehydration can make fine lines look even more noticeable.