The Osmo Action is the first actioncam of DJI. It's a very good first try for DJI, but most reviews on youtube are sponsored by DJI and that's why they only point out the positive features of the Osmo Pocket.
When you watch the more independent reviews, you will see that there are a couple of negative things to say about the osmo action.
I heard that hyperlapse didn't work very well, the screen on the back has a delay of over 0,5sec (sounds minimal, but it's extremely annoying when capturing fast shots.) and it doesn't have the wide angle as GoPro has.
I think that the years of experience that GoPro has, and the millions of accessoires you can buy everywhere, make the GoPro 7 black a way better choice. Although I must say that I have not worked with the DJI action.
Bottomline is that I want to mention that the reviews on youtube promise you the world about the Osmo Action, but I strongly doubt if this camera can fulfill all promises.
Edit: this is one of the videos where they genuinly talk about the negative sides of the osmo action that no one else seems to talk about. Offcourse it's always one word against the other.