The first apostles WERE the first Bishops!
And they have appointed bishops down the line. Of course there are apostles today!
Holy Orders has three steps —
Diaconate
Priesthood
Episcopate
I realize this may not be what you believe, but there is an unbroken line of succession to the apostles in only one place.....the Catholic Church.
I understand the theory. It can't be proven one way or the other, but it really doesn't matter. Apostolic succession through a particular line of men as a mark of the Church is not an apostolic teaching, i.e., it's not taught in the Bible.
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. (Apostolic Succession)
There are no apostles today. One qualification of an apostle was to know Christ face to face and be a witness of the resurrection (Acts 1:21-23).