>>92499It depends on what you're trying to achieve, if you're trying to achieve one goal than watching one replay of another person that achieved that goal is all you need technically. However, that doesn't necessarily mean that the person you're watching is doing things effectively, so it's not a good idea if you want better in the long-term, and what's better in the long-term is watching multiple replays from different players and comparing them. Also when you download a replay you can watch each stage individually and fast-forward so it's not hard to go directly the part that you need to see.
And usually in my experience when I've tried to look up runs on Youtube I usually get results from the same few channels with the highest views and the replays themselves are typically old (10+ years old) and not the greatest unless it's a world record from recent years.