I used to think that way, too, Mrs Sally, but after my spouse died, I asked the priest if MY offering the mass was as grace-filled and meritorious as the priest’s. He said definitely - the only difference is that he must make the mass HIS intention, but both of us are able to unite in the one offering and obtain the grace of the intention in fullness. The degree obtained by the celebrant is not higher than that of our own intention.
If I am wrong, I stand corrected, but that was my understanding and I trust this priest for his liturgical knowledge.
True, he can consecrate and present our prayers to God, etc., but that doesn’t limit our own offering together with him, as something less meritorious.