My attempt to define "strict global consensus":

- A strictly ordered and objective list of transactions,
- that everyone on the network agrees to exactly,
- in near real time

If some element of an application necessarily requires these, use blockchains; for everything else there are much better solutions

agreed, but only if participants in the network default to untrusted. If you control all participants (even across great distance) or you can expect them to behave well because of external factors, don't use blockchain