Quoting the tl;dr in the linked article:
Samsung could be stepping up its game by offering seven years of major Android updates for the Galaxy S24 series, and the generous update policy might extend to other Galaxy flagships.
The Galaxy S24 series might also introduce charges for AI features like Live Translate and Pixel-like photo editing tools after 2025.
There’s speculation that users may need to sign in to their Samsung accounts for certain AI functionalities.
Sony covers most of those, but they are not cheap.
You can get last year’s model or the year before that cheaper. It’s not like there are huge differences year over year anyway.
But Sony only provides 2 to 3 years of software and security updates, so getting an older model might not be the best idea either.
You can switch to a community ROM like Lineage when they stop. They’re A/B devices that support GSI images, you can install any GSI UI over the Sony firmware. In practice some of them support more features than others but they do work.
Also, I wouldn’t get my hopes up about all these promises about 7 years of updates. Google is notorious for going back on their word and Samsung only parrots them to look good
I honestly don’t see either of them delivering. Even if they wanted to, neither of them has the logistics for long term support of their devices and I doubt they’ve developed them overnight.