I don’t know about anyone else but when I bake a cake, unless it’s for an event, I use half then slice and freeze the other half.
Before freezing the cake I always slice it as that makes it so much easier to grab out a piece. Just pop in container and take to work or school for lunch, it will be defrosted by morning tea.
Therefore I have a tendency to make my cakes square, in a slice tray or in a loaf tin. Why not round cakes? Because I find wedge pieces of cake don’t fit in my containers very well and a nice square piece or a rectangular piece of cake fits in so nicely.
An alternative to above is to bake your cakes in muffin trays or cupcake moulds. Just because the recipe says layer cake does not mean it can’t be baked in a slice tray or as cupcakes. Make them to whatever fits your needs best.