Comment by theMMaI

Most devices still support S3 sleep, it's just disabled by default as s2idle (modern standby) has become the default. You can almost always re-enable S3 sleep if you really want to, but on modern devices it typically only takes a few seconds to resume from S4 (suspend-to-disk) which technically is safer and more reliable. Also you can always use suspend-then-hibernate if you really want fast resume during the day, but long battery life when it's more than an hour or so.