zwift is offering very little in terms of logged data. the only thing there is is an overview of rides you did with distance, time, overall elevation and average watts. the data sheet you get to see at the end of the ride with power and heart rate curve etc is not logged.
(edit: your ride data is saved as a fit-file, which contains a whole bunch or ride data. zwift has just decided to not log and display all of it for some reason.)
the free apps log a whole lot more data. strava for example, also logs gps data (watopia island or your real trip if you ride outdoors, of course), heart rate, speed, average and max power, terrain profile, cadence, calories, weekly stats and your segment times and the respective leaderboard (your ranking on that segment).
the only one thing necessary to do if you ride on a single account is adjust the avatar when you ride on zwift, especially weight and ftp if you intend to do a training session.
zwift can automatically upload your ride data (which is saved as a fit-file) to strava (or other apps if you prefer) for you to look at so there isn’t even any hassle with it.
in my household (3 riders) we created a strava group and can easily compare our rides, weekly activites, etc.
all this only becomes meaningful if you feel like looking at your collected data at any given time, for either fun, comparing with others or planning your training. if you’re happy with the zwift log, then that is of course fine, too.