You can use monolog for a php application, later maybe it's interesting to use something like ELK to centralize all the logs.
In my company still have not a nice way to collect logs, but for me the idea is to go with something similar to ELK or like Loggly, Logz.io. If you are using AWS or GCP you can try their solutions too.
My idea is to split logs per type or error level and have a nice split between logs :)