I haven't really tried using Pocket and know only a little about it, so correct me if I'm wrong.

In general:

- With Notion, you can customize the database you have like adding tags (categories) which can be useful if you want to organize your data as you want

- The automation is not limited to these three, you can actually add more platforms, like an email of your favorite newsletter to the Notion database if you want to

- You can do a lot more customizing stuff in Notion

Twitter & YouTube

- With Notion: On my phone and tablet, I can save the tweet/thread I like without getting out of the app and just mention SaveToNotion. And with YouTube, I only have to save it to a designated playlist

- Pocket: If I open from the phone or tablet, I have to copy the tweet/video URL and save it to the pocket app manually, and the saved data is URL only

URL:

- It's actually the same with pocket, but with Notion you can customize your data more, like adding tags or any data you want to have more information in your database. It can be used for organizing stuff and more.

But to be honest (subjectively), it's because I just love using Notion :)