If you were going to bother, you'd split Amazon and AWS. Amazon becomes mostly a retail company again. Without the AWS subsidy margins, they'll be down to retail margins and the ad business (with ads, it's plenty). They can perhaps keep the gadgets, splitting every major aspect apart might be going too far.

AWS is a $400 to $600 billion market cap company right now if it were trading on its own, based on its operating income and the insatiatable market demand for anything cloud. The ticker is even available conveniently. They'll get to $150+ billion in sales and $25+ billion in operating profit in the next six to seven years (average of 21% annual growth over seven years; very much within reach). It might approach being a trillion dollar company a decade from now (at MSFT type multiples).

You'd split Facebook and Instagram as the most obvious separation line (and then do something with WhatsApp, it can be spun off or go with either or; FB already has messenger, so it probably shouldn't go with that entity).

Instagram is a $100+ billion publicly traded company on its own plausibly. There is some question on erosion in both FB and Instagram once you detach them from eachother. They both lose a huge protective moat and cross promotion (Instagram has become a lot more mature at this point, it'll be more at risk to userbase erosion going forward, versus say five years ago; and FB is definitely at high risk for userbase erosion with fewer moats).