You missed the key criterion, which is being able to see the logs from that process "as a text file", or the way I'd rephrase it "with the same ease of a text file."

Kibana is ok (definitely beats grep) when you want to look across a fleet and determine if a specific thing is happening. But when you have a specific symptom that happens on a particular instance, what you want to do is see logs in the order they happened, and Kibana isn't close. Querying and viewing logs are just slow and cumbersome relative to less/grep.