Notion is a hierarchical note-taker/wiki with some additional features like simple databases, task lists etc.
They are not the same kind of software.
Also, you can link notion pages. They have a block element that is a link to another page and for inline links you can use the regular link (each notion page has its unique, stable url).
Notion does but it's not well implemented. If you copy a link to a notion document and paste it in another it does create a link. Wish they made it a little more well defined though (I don't want to copy a link and paste it).
