We at Moesif (https://www.moesif.com/solutions/track-third-party-api) released a similar tool in 2017 and found that many of our customers including Deloitte, UPS, Snap Kitchen, iFit, and Trung's previous company, Snap Kitchen were looking for a way to track APIs without the complexity of a full service mesh like Envoy. Especially if you're hosted in something that cannot run an on-prem service mesh or gateway.

We're a little different in that we also support agent-based rather than just proxy. Meaning we have an SDK that sits out-of-band.