You can thank Microsoft for the current mess. S0ix (aka "Modern Standby") doesn't even work right on Windows.
Linux Laptops with no S3 support use S2, not S0 as on Windows. Still buggy as hell. My XPS sometimes loses 70% in 4 hours standby and then just ~5% in 2 days of standby. Most of the time the battery drain is insane. At least the overheating in bag issue never occured to me.
Linux 2023: Sleep support doesn’t work quite yet, but it’s being worked on right now