In common law, the foundation of the courts, their original or inherent jurisdiction is in-person. This is the meaning of jurisdiction, the place of the speaking of law.
In-person is the basis for natural justice which is a multi-facted gem concerning impartial hearing, the right of representation, the right to present evidence and to impugn evidence, the right to cross-examine, the right of presence before a judge to have him assess these tangibly, all necessitating actuality, imperatively in-person.
Involved in this are issues of procedural integrity like isolating witnesses during examination, fair hearing as well as cogency in development of evidence.
Disputes on land title and derivations necessarily must come up live before a judge and be determined in a real way; otherwise the line of authentic title would be impeachable and the root will stay in question.
There are many other examples.
There is also the matter of practical troubles that make internet hearings hazardous, unpredictable and un-predicable. The upshot is that in-person hearings at the very least must remain for election by any party; and some cases absolutely must happen in open court regardless of any party’s preferences.
As a matter of justice and caution, though, internet proceedings should be relegated to mere organisational aspects in procedure like setting dates or acknowledging notices and answering direct summons from the judge when allowable.
Thus tribunals that are conducting hearings via internet could already be acting ultra vires and remain subject to judicial review.