The present-day version of the tracer does allow us to control the content to trace based on the rulesets and rule types filters before the trace begins. A lot of times, especially in production environments, for debugging critical issues, we will need to do an elimination-style investigation wherein we start off with the raw data and quickly sift through the problematic areas. 

I understand we can download the trace session and there are Pega internal tools to do the filtering but it seems quite cumbersome and unnecessary compared to filtering out the activities or connect-REST calls right there in the production environment, making issues fixes a lot easier.