Lambda calculus is somewhat interesting in my opinion because in addition to being really simple, it’s actually a pretty usable language. You could use it as a

Lambda calculus is somewhat interesting in my opinion because in addition to being really simple, it’s actually a pretty usable language. You could use it as a basic template language without much modification. The same cannot be said for Turing machines or SKI calculus (the latter in particular since it has no natural IO mechanism).