Server side tracking is useful for logging http requests. Client side tracking is useful for logging user interactions. Used to be there would be a small differ

Server side tracking is useful for logging http requests. Client side tracking is useful for logging user interactions. Used to be there would be a small difference between server and client due to caches and user settings... but... Modern apps (i.e. React, Vue, Angular) often only load one page, and then all interaction is managed by client side code, so often client side tracking is the only thing that works.