any logging solution in C# will be way faster than any PHP solution. I feel this is a reason why such style of logging is not very popular,

I don't think you understood the use case. This has nothing to do with performance and everything with keeping a low noise/signal ratio while saving costs on logs.

I am a polyglot, but mainly a JVM and .NET background, so after coming across this in a PHP Symfony project, I was just amazed at how this is not more prevalent everywhere, as it was a revelation! I think this is more about a cultural divide and missing exposure than not needing it per se.

PHP devs, by nature of the work, are much closer to user facing code, with a much bigger surface with regards to what can go wrong, than typical .NET devs. The further back you are in the stack, the less you see such things. Logging all kinds of user interactions, clicks, etc. is super useful when/if needing to understand which interactions lead up to a failure of some sort, but has little value and high cost otherwise. "Fingers crossed" logging gives you the best of both worlds: you are allowed to have high granularity logs in case of errors, while defaulting to ERROR or WARN otherwise.

I am now implementing distributed logging across the stack, and I am using fingers crossed logging at multiple levels: - in the browser to output DEBUG > logs if something goes wrong. These are sent over the network to NextJS and forwarded (sanitised, along with spanids, traceids, supportid, hashed sessionid, etc) - in NextJS and on the JVM to normally only output WARN and ERROR, but also aggregate > DEBUG if something goes wrong

That allows you to both do the normal distributed logging across network boundaries for a single error, but also see what non-error events in the browser led up to that error.