I've been searching the web on the advantages of using array formula vs
SUMPRODUCT. I have come across the following in my searches:

"The problem with SUMPRODUCT is that it is not a standard Excel formula.

It relies upon an add-In, which is fine until someone doesn't have that
particular add-in at which point it all turns to custard with the beautiful
model you have built, and credibility hits rock bottom."

Is it true that SUMPRODUCT is not a standard Excel formula?