You can argue that and many sites are indeed scoring it higher (Wired 9/10, Gaming Trend 9/10, GamesRader 9/10, Game Informer 9.1/10, CGMagazine 10/10, Digital Spy 10/10).
IGN's 2 negatives are that PS5 only has a few games not playable on PS4 and that its SSD is only 667GB. These points also apply to Xbox Series X but for instance PS3 didn't share its exclusives with PS2 and its small HDD wasn't as big of a problem as games were read from disc at the time. While it also had full BC with PS1 and PS2, it of course had its fair share of other problems.
So like always, scores are subjective and I really do think an 8/10 is reasonable.