@pratik A lot of people think of Drafts as a tool for capturing text and then routing it to other destinations. I use Drafts as a destination in itself, due to how extensible it is (I've built a number of actions that suit the way I work), and how well integrated it is with i(Pad)OS (my primary working platform. Also possibly due in part to the way I came to Drafts in the first place (Folding Text / Notational Velocity on macOS --» Editorial on iPad --» Drafts).
I use Drafts for two main activities: daily logging (daily notes, workouts, contact notes, other random operational notes that crop up as I go— most of which are automatically referenced in the day's daily note), and drafting things (creative writing, blog posts, Mastodon posts, newsletters etc). There's a layer of "note-making" and knowledge wrangling I can manage to an extent in Drafts but benefits from the tools available in Obsidian (easier back-linking, graph visualisation, canvas etc).
It's really easy to send ntoes to Obsidian (again, that's the kind of activity Drafts was originally designed for). And I can easily link to Obsidian items in a draft if I need/want to. Some people are probably doing everything I do in Obsidian alone, but I'd miss the deep OS integration (Widgets! Scriptable access to calendars and reminders! etc) and the workflows I've already built— not planning to learn how to build an Obsidian plugin any time soon...
Also, I think the separation of modes serves well— Drafts remains open constantly; Obsidian is opened for refining ideas (beyond my own writing) and cultivating connections between ideas. In the past, I've done some of this connective work through concept maps, where my concept maps would reference notes or searches in Drafts. Obsidian's more robust for this.
Last thought: the pairing provides a kind of self-sustaining loop. Drafts facilitates my day-to-day momentum; Obsidian is a home for continually refined learning/knowledge; that learning/knowledge feeds back into things I write in Drafts.
I'm enjoying the pairing thus far. Again, while I've spent a lot of time in Drafts, I'm still picking up on Obsidian usage, so we'll see how things evolve...