Depositions must always be attended by a court reporter in every jurisdiction I have ever encountered (including Colorado, New York, California, Wyoming and Florida). Alaska may be an exception. It's state constitution creates a right to participate in many kinds of legal and legislative proceedings remotely because the distances involved are often so great.
The court reporter administers an oath to the witness, keeps track of exhibits, impartially records what happens (usually stenographically and with an audiotape) and then reduces it to a transcript later, a process assisted by having been there when the testimony was given (and allowing for the court reporter, for example, to request spellings of words during breaks).
A videotape can be used in addition to the court reporter and sometimes this is done when it would be helpful for understanding a highly visual topic (e.g. in a patent case where someone is explaining a 3D object) or when a witness is expected to behave badly or is known for problematic voice character or body language.
Court proceedings in a courtroom are often audiotaped with a judge present but without a live court reporter present. Appellate court arguments are frequently live streamed over the Internet.
There may be some jurisdictions where it is possible to have an oath administered by a notary and simply audiotape or videotape the deposition, but that would be very rare in every jurisdiction of which I am aware.