You are stuck on believing “church” means the RCC gathered together with a priest in a “holy” building.
St Ignatius of Antioch was a disciple of the Apostle St John. Let us see what he has to say about the Church:
IGNATIUS to the Smyrnaeans
CHAPTER 8
8:1 [But] shun divisions, as the beginning of evils.
Do ye all follow your bishop, as Jesus Christ followed
the Father, and the presbytery as the Apostles; and to
the deacons pay respect, as to God’s commandment. Let
no man do aught of things pertaining to the Church
apart from the bishop. Let that be held a valid
eucharist which is under the bishop or one to whom he
shall have committed it.
8:2 Wheresoever the bishop shall appear, there let
the people be; even as where Jesus may be, there is
the universal Church. It is not lawful apart from the
bishop either to baptize or to hold a love-feast; but
whatsoever he shall approve, this is well-pleasing also
to God; that everything which ye do may be sure and
valid.
So you are correct. The “Church” is not the RCC.
It is the RCC and all the Eastern Catholic Churches and the Orthodox Churches. It is all the Churches with validly ordained bishops, priests, and deacons. It is all the Churches with valid sacraments and Apostolic Succession.