SSPV, CMRI, and those associated with the late Bp. Dolan are sedevacantists.
RCI (which is headed by Bishop Donald Sanborn) and some other foreign apostolates like IMBC from Italy are sedeprivationists (which posit that the Vatican 2 pontiffs were duly-elected with legal title to the Papacy, yet did not formally attain to actual authority or jurisdiction due to their own impediments).
Either way, a long interregnum, although mysterious, is preferable to a Church that formally teaches error or introduces poison to her flock.
“...a Church that...”
You know, I presume, that the Church, being the spotless Bride of Christ, can not and does not teach error.
Wayward priests and prelates, by contrast, can and often do.
Christ’s Church exists, always exists, is always both visible and discernable, and of course the gates of hell will never prevail against her.
Does SSPV claim it is the Church?