What a bizarre claim.

Prometheus scrapes the same text format as OpenMetrics 1.0 and over 700 public exporters use this format, and there are TONS of other non-Prometheus software that consume the exact same text format. Prometheus's biggest competitor, Datadog (which is not open source mind you), consumes it too. I think even Grafana consumes it directly. It's becoming an IETF standard[0].

Would I have preferred JSON over a custom text format like this? Yeah. But to claim an open source project like Prometheus with effectively no business at all is using a text format like this to have vendor lock-in? That's quite a stretch.

[0] https://github.com/OpenObservability/OpenMetrics/blob/main/s...