The main benefit of online yoga is that it allows you to exercise at home, on your own schedule. More and more people turn to online yoga. Some prefer this option because they don't live near a studio, or because they travel a lot, can’t fit a studio class into their schedule and many more barriers.
There are plenty of great YouTube Yoga teachers, my personal favorites are Yoga With Adriene and Yoga with Kassandra.
However, for obvious reasons, YouTube videos, or any kind of pre-recorded videos are not as beneficial as 1:1 personal training. A personal trainer can give you meaningful feedback and help you stay motivated. YouTube fitness channels and fitness apps can be a great supplement to your fitness routine, but they lack the mentoring and motivating effect of a personal trainer.