I remember, that was a dramatic change.

Also, most people now dont remember this, but YouTube was initially popular because their flash video player was efficient, worked acrossed many different system configurations and browsers and dynamically changed resolution to match your connection.

At that point you had some people with broadband connections and a lot more with dial-up. So often dial-up users would not be able to watch videos because they were only available in one resolution.

YT had 144p (or less!) videos ready for dial-up users and higher resolution videos for broadband users and it automatically picked the appropriate video for the client. This made it so most people (dial-up users) would look to YT first, because you knew that YT would have a video that you could actually watch.

Then Google bought them.