I believe there was a time that Samsung was worse with releasing updates to their own unlocked phones than the carriers.
It's a mixed bag with Samsung and varies between models. One thing is for certain, they really don't care about supporting a product after it's launched. Only if there is a glitch like the autofocus on the Ultras and then they'll work on it because it has enough attention that they have to for the next year.
Then they push push out their 2 OS updates and then their 3 years of monthly security updates to show they care... and then go quarterly on ya.
All the while Apple just announced... the iPhone 6S... that was released in 2015 wth iOS 9... will get iOS 14 when it's released later this year... Which basically means six years support.
One question I have been having recently about Samsung OS support... The Note 20+ will be released in a couple of months with Android 10... probably just a matter of a couple of weeks before Android 11. Because Samsung is so late after Android releases OS updates... they are going to count Android 11 as one of our two OS updates and then Android 12 a year later and that's it. We will miss out on Android 13 because 11 was released two weeks after the 20 was. To me... Just doesn't seem right lol.