My friend briefly worked at a company where every API was a lambda. Each lambda had a git repo. Lambdas would often call into other lambdas. In order to make a feature, it might involve touching 10+ lambdas. They had over 200 lambdas after a year. Total nightmare
I think the major issue that I see, and I could be wrong is that if you want to change some underlying functionality between you and a dependent function to do that you would need to change all the intermediate functions only so that you could call that dependent function and layers deep.
I have played around with architectures like this, but I allowed the caller to patch in a dependent function in the call with those function overlay overrides were passed from function to function.
