For any modern dotnet system, distributed tracing is already built in to the default web client, server, and other operations.
You can see this with a basic example, by configuring your logging to display the correlation identifier. Many logging systems, such as Elasticsearch, display correlation by default. The identifiers can also be passed across messaging, such as Azure Message Bus.
Logging has always been a useful way to understand what is happening within a system and for troubleshooting. However, modern systems are very complex, with multiple layers and tiers, including third party systems.
Trying to understand what has happened when a back end service log reports an error, and then correlating that to various messages and front end actions that triggered it requires some kind of correlation identifier.
This problem has existed ever since we have had commercial websites, for over 20 years of my career, with various custom solutions.
Finally, in 2020, a standard was created for the format of the correlation identifier, and how to pass the values: W3C Trace Context. In a very short amount of time all major technology providers have implemented solutions.
The examples below show how this is already implemented in modern dotnet.