“Even if it were historically provable that there was an unbroken succession of bishops from the first century to the present day Roman Catholic bishops (and it is not), Protestants would still demur to claims of Roman authority based upon apostolic succession. It is the apostolicity of the church that counts. And it is precisely by the standard of apostolicity that the Roman Catholic Church is measured and found wanting.”
Where does your definition of ‘apostolicity’ first appear?
OPn Apostolic succession.
Acts
21 Therefore it is necessary to choose one of the men who have been with us the whole time the Lord Jesus was living among us, 22 beginning from John’s baptism to the time when Jesus was taken up from us. For one of these must become a witness with us of his resurrection.
This is what the Apostles required. Whom today fulfills these requirements ?
There is another element besides your observations. The position that the priest or minister must be free from sin before he can administer sacrament.( I’m aware that the Donatist position was condemned.)However the question arises what if serious sins are prevalent among the priest and bishops FOR CENTURIES? In short an apostasy of the Church leadership. God can withdraw from such a people.