You are doing something wrong xd
Battery is an area where smartphones unfortunately didn't progress at all. It's not that the S9 is a bad phone.
you're using it wrong bro my s8+ has battery for 30~ hours I've no complains about
use zenphone 4 max pro for Battery
and maybe youre using 1440p resolution you can go lower like 1080p
battery life doesnt really progress on phone because the usage gets higher and higher
You are using it wrong, my s8+ hold for whole day with heavy usage
Samsung is trash - imo. My S3 mini (first one) had a shitty battery that couldn't last more than a 3rd of the day, S5 had battery issues too (but was overall actually ok, no other mistakes so the best of the bunch), S6 bottom plug where you could insert the charging cable kept breaking like crazy (and I've had three different S6's, all the same problem), S7 broke after 14 days to the restart loop failure for no reason, and I noted one of the Notes had a battery eksplosion issue.
Seems to me like they do not know how to develop anything properly, but haven't tried S8 nor S9.