Opentelmetry is definitely a good thing that will help reduce vendor lock-in and exploitative practices from some vendors when they see that the customer is locked in due to the proprietary code instrumentation. In addition, opentelemetry autoinstrumentation is fantastic and allows one to get started with zero code instrumentation.

Going back to the basics - 12 factor app principles must also be adhered to in scenarios where opentelemtry might not be an option for observability. e.g. Logging is not very mature in Opentlemetry for all the languages as of now. Sending logs to stdout provides a good way to allow the infrastructure to capture logs in a vendor neutral way using standard log forwarders of your choice like fluentbit and otel-collector. Refer - https://12factor.net/logs

OTLP is a great leveler in terms of choice that allows people to switch backends seamlessly and will force vendors to be nice to customers and ensure that enough value is provided for the price.

For those who are using kubernetes you should check the opentelemtry operator, which allows you to autoinstrument your applications written in Java, NodeJS, Python, PHP and Go by adding a single annotation to your manifest file. Check an example here of sutoinstrumentation -

                                                 /-> review (python)
                                                /

frontend (go) -> shop (nodejs) -> product (java) \ \-> price (dotnet)

Check for complete code - https://github.com/openobserve/hotcommerce

p.s. An OpenObserve maintainer here.