It can be difficult to fairly compare the outputs of the two cameras because one of the main advantages of the larger sensor is there's a lot more flexibility in the raw file to improve the image. Small sensors like the
Mavic Air 2 have very little latitude in the raw files and while the
Mavic 2 Pro's 1in sensor is the smallest of the 'big' sensors it's still a big improvement and it's possible to pull back up to a couple of stops in shadows and highlights such as below:
For those that are used to processing raw images from larger sensor cameras they'll know the benefits the
M2p's larger sensor brings but for those who work with jpegs straight from the drone, you're not likely to see much if any improvement from the
Mavic 2 Pro. That's in no way critical of the
Mavic Air 2 nor suggesting it isn't capable of great photos, I've seen people disappointed with the
M2P because they've used it with jpegs and not seen the benefits they expected.
Pixels seems to be frequently treated as equivalent but they're not, the
Mavic Air 2's 48MP sensor cannot capture four times the detail of the Mavic Air's 12MP sensor nor is it going to allow an extreme amount of cropping. Aside from marketing packing huge pixel counts onto small sensors doesn't bring significant benefits and it's noticeable that the megapixel wars on larger sensor cameras died off many years ago. Sony who manufacture both the
Mavic Air 2 and
Mavic 2 Pro sensor released their RX100 compact with a 1in 20MP sensor in 2012, the A6000 mirrorless with an APS-C 24MP sensor in 2014 and the Sony A7 with a full frame 24MP sensor in 2013. Since then they've released six more versions of the RX100 series, five more a6xxx cameras and two more A7x cameras with continual sensor improvements in each series but still the same number of pixels with the RX100mk7 still 20MP, the A6600 is 24MP and the A7Mk3 is 24MP.
Their R series is an exception with 34MP in the first generation, 42MP in the second and third generation and now 61MP in the current fourth generation but read pretty much any review of these cameras and you'll notice large caveats from the reviewers that to get the benefit of the higher resolution needs very good lenses and technique. Even the 61MP on the A7Rmk4 is still very different to the 48MP on the
Mavic Air 2 because the full frame sensor is significantly larger so the pixel density is still comparatively low.