There's just a lot of it. Each series is relatively self contained. The original series and next gen are both very episodic and you can pretty much just pick a random episode and go. It's not that complicated of a wold, there's just been so many episodes that if looked at as a whole it seems like a lot, but if you just sit down and watch it, it's very approachable.

I found a YouTube link in your comment. Here are links to the same video on alternative frontends that protect your privacy:

• yewtu.be
• inv.nadeko.net
• yt.artemislena.eu
• piped.video