Hey, this isn't the sort of telemetry we are talking about with OTel.
About the only "privacy concern" with otel is that you are probably shipping traces/metrics to a cloud provider for your internal applications. This isn't the sort of telemetry getting baked into ms or google that is used to try and identify personal aspects of individuals, this is data that tells you "Foo app is taking 300ms serving /bar which is unusual".
After I added OTel to an open source project I run, I spent a bit of time arguing with someone about telemetry - they kept saying they didn't opt in and that we need to inform our users about it, etc., and I kept saying no, that's not the same type of telemetry. I wonder how common this misconception is.
Client-side transport is pretty unusual with OTel. I think almost everybody is sending things from the server side, so I don’t think your concern is usually relevant.
I think you are more talking about RUM which isn't yet supported by OpenTelemetry. I think they are working on it.
I am not sure if it will support session replays like some vendors like Sentry or New Relic offer. Technically, I think session replays (rrweb etc) is pretty cool but as a web visitor I am not a fan.
About the only "privacy concern" with otel is that you are probably shipping traces/metrics to a cloud provider for your internal applications. This isn't the sort of telemetry getting baked into ms or google that is used to try and identify personal aspects of individuals, this is data that tells you "Foo app is taking 300ms serving /bar which is unusual".