Here’s my understanding, based on a radio source I’d rather not name in case I’ve made an error in my memory or my presentation.
The Church of England originally had all seven valid sacraments, since its clergy, including its bishops, were Catholic bishops that broke away from the Church. During the reign of Henry VIII, Anglicanism remained mostly Catholic in its beliefs (except a few key ones to justify breaking with Rome, suppressing the monasteries, etc.). It was later on in the same century, under Edward VI and Elizabeth I, that they became more Protestant in their beliefs and practices. It was around that time that the sense of a sacrificial priesthood was lost. A part of the form of the sacrament for ordaining a priest (or, therefore, a bishop) is the intent to ordain the person to a sacrificial priesthood. With the idea of a sacrificial priesthood lost, new ordinations to the higher levels of Holy Orders were invalid.
Whether ordinations to the deaconate were still valid for that first generation, when valid bishops were ordaining but without a sense of sacrificial priesthood, is an interesting question. Maybe there was a phase (around the time of Shakespeare, I suppose) in which many Anglican “priests” and “bishops” were validly ordained deacons. But a deacon can not validly ordain anyone, even to the deaconate, and so Holy Orders was eventually lost entirely.
Without valid Holy Orders (specifically priests and bishops) there can be no Eucharist, no Reconciliation, no Anointing of the Sick, and I believe no Confirmation either. Anglican baptisms would still be valid, and marriages as long as neither party is canonically Catholic (or, if one is, if he or she has done everything that needs to be done for convalidation).
Today, some Anglicans have regained a sense of sacrificial priesthood, but it is too late. Apostolic succession has already been ruptured, unless a particular priest or bishop traces his line of ordination back through some line, outside the Anglican Communion, that does have Apostolic succession.