Why these two, and not something more common
Cream cheese is thick, tangy, and firm enough to hold its shape at room temperature — three things most soft cheeses don't combine. Mascarpone matches the texture and richness almost exactly but is noticeably milder and slightly sweeter, since it's made from cream rather than cream plus a tangy culture. A blended Greek yogurt and ricotta mix gets closer to that tang (from the yogurt) while ricotta supplies the body, though the result is softer overall and won't set up quite as firm in a baked cheesecake.
Where each works best
Mascarpone is the better pick for frosting and no-bake fillings where richness matters more than tang — it whips smoothly and holds its shape well. The yogurt-ricotta blend is a solid everyday swap for dips, spreads, and bagel-style uses where a little extra tang is welcome, but expect a looser final texture in anything baked, like cheesecake, that relies on cream cheese firming up as it cools.
FAQ
Will either of these work in a baked cheesecake? Mascarpone works well and bakes up close to the original. The yogurt-ricotta blend can work too, but the higher water content means a softer set — draining the yogurt through a cheesecloth for an hour first helps firm it up.
Do I need full-fat versions? Yes — low-fat Greek yogurt or ricotta adds extra water without the richness cream cheese brings, which shows up as a thinner, less stable result in both frostings and bakes.