With modern trends, online coaching is very relevant, even more than you think. I categorically do not support Renato Canova in his statements that the coach should be personally present, as he himself claimed that the modern world of running requires regular participation of an athlete in races and training with one or two peaks per season (Lydiard training system), but with higher indicators is no longer relevant, the world dictates a different approach.
So online coaching is the next step too. After all, judge for yourself, with the current technologies, all sorts of gadgets, the Internet, we can absolutely easily control, analyze and draw conclusions on almost any parameters of an athlete.
Yes, I agree with Renato Canova that the best training process is in a group, when there is a certain and sufficient density of athletes of different levels without sharp changes and a leader, then the athlete achieves better results than when he would train alone or in a group where the density is poor (large gaps in the level between the strong and weak).
If you have a good and proven methodology, then it will work remotely. Another problem is that there is an elite world and the world of hobby joggers, but the number of hobby joggers far exceeds the number of elite athletes and in terms of business as an online coaching hobby joggers is more relevant, profitable and promising.