He knew AM4 had lots of gains but didn't know whether a measly 5% would be all you got via AM5 from the upgrade to zen 5 from zen 4. It wasn't known at the time that AM5 would continue to zen6 and zen 7 and the public doesn't know what the performance of those cups will be.
Isn't the point of shopper advice YouTube channel to give advice to shoppers, which sometimes means making rational assumptions about the future?
Steve made horrible assumptions about the future and gave his audience bad advice that (AM5) platform longevity is irrelevant.
Just from 7700x to 9800x3d, the performance uplift is 33%, while dead end Alder Lake had low single digits and another dead end Arrow Lake had a performance regression. Zen 6? Could easily be +25%, already getting to +66% combined.
By discounting platform longevity, he made those 2 horrible platforms (dead end Alder and dead end Arrow) equally valid to long life AM5 platform.
You're implying that since AM4 was good, that AM5 would also be good for platform longevity. If 5% is all you got from the first upgrade gen, and if AMD hasn't yet confirmed zen 6 and zen7 support for AM5 then what he says is totally valid. Not sure what you're missing.
In discussion about longevity, AM5 _
HAS_ longevity, even more so than AM4.
As far as gen-on-gen performance improvement, you can take average of past improvements, or you can take a single outlier.
Steve did the dumb thing of taking a single outlier and made a projection on a single outlier rather than taking a broader average, such as that of the generations of AM4 platform from first to last.
Steve also, effectively, equalized the insanity of Intel platform changes to highly consumer friendly AMD approach of extreme platform longevity, by implying (based on faulty assumption) it would be pointless to upgrade any more frequently than longevity of a socket, which in case of AM4 was 5 years (even though the uplift was 124%) and in case of AM5, > 8 years between upgrades.
Further, he implied there would be no CPU only upgrade, only full system upgrades (by discounting platform longevity as irrelevant).