Why not recited, performed, or delivered?
I know you're trying to be a smart arse (don't try, you're not clever enough) but it's an interesting question (rhetorical though it's intended to be). It's the kind of discussion we might have had during those long years of daily religion classes in the convent school. 'Sister, why do we use 'to say Mass?' Then, the nun, instead of giving us some pat answer, would ask us to put forward our hypotheses and we'd have a great old chinwag about it.
The really correct term is not 'say' but 'offer'. Mass is a sacrament (basically it's window dressing around the Eucharist, that's the sacrament part) and it's therefore offered. The part of the Mass where the Eucharist is done is actually called the Offertory. If you can go to Mass in Ireland, the priest will always use the term 'offer' when he's reading out the list of forthcoming special Masses. For example: 'Mass will be offered for the fifth anniversary of Mary Murphy on Wednesday 10th March.' or 'Today's Mass is offered for peace in Ukraine'.
But as to the use of said, here's my take. Mass is a form of communal prayer. The congregation participates in it so it's not delivered. It's prayers lead by the priest. But because it's more than just saying prayers and involves readings, a sermon, singing and the offering of the Eucharist, it's not recited either. Performed could be nearer to the mark , because it is more akin to a rite or series of rites than an actual prayer. The Mass is a ritual performed by a priest and congregation together. But of course Mass does not require a congregation. A priest can offer Mass including Communion entirely on his own.