Almost nearly alike.

The phrase you're looking for is "almost similar." This succinct expression captures the essence of being nearly or near to matching in terms of quality, appearance, or performance, though not completely identical.
In another context, where a precise term for 'a nearly equal number or amount' is necessary, "nearly equal" could be used. This phrase serves to denote approximate sameness or nearness of equivalence, despite slight discrepancies that would keep them from being exactly the same.