Haha we’re almost the same. I’m using an S9 right now and it’s only getting 2.5 hours of a screen on time, was considering the S23 Ultra since it’s deeply discounted. I cannot believe how pristine my S9 is even though I used it with no screen protector for almost 6 years, feels like a big waste to get rid of it.
Main factors for me - improved security since my phone stopped getting updates a year ago and my work stopped access to my emails due to lack of security patches. Improved camera for general use. Can play some newer games, some mobile games are seriously impressive these days, Genshin, Star Rail, upcoming Zenless Zone Zero.
Also not from the US, I went from s9 to s23 mainly because the s21 and s22 we have are exynos but s23 are snapdragon. The rumor is that the s24 will be going back to exynos so the s23 is our best and only chance for us non-USians to upgrade and nab that sweet snapdragon!