Good to see some of the balanced reviews below. IMO - it depends on one's expectations. The 11yr boy old enjoyed it which is probably what counts the most. The 16yr girl old stayed off of tiktok to watch most of it but probably wasn't as impressed. The spouse who thinks the HB universe only contains families of the past (Flintstones), future (Jetsons) and present (Scooby DD) was thoroughly disappointed. I had low expectations and freaked everyone out when I unexpectedly (to myself also) screamed "Caaaaptaaain Caaaaaaave mAAAAN" - so it hit my nostalgia button hard giving it max stars. So, if you expect to see a old school Scooby show, it is not. It is more like a Once Upon a Time crossovery type show. Crossover like Avengers uniting - not Spawn, Spidey and Supes in one movie. That may go over the heads of those who think they know Scooby/HB universe.
Anyway, its sort of a reboot and seems to use the scatter approach. It tries to introduce Scooby to those that don't know the HB universe, keep those that do know entertained (i.e. cameos) and with adult jokes, and the neutral with historical & social contexts (i.e. greek mythology, reality TV). Plus an overarching 70s/80s type of lesson - this one on friendship.
The graphics were surprisingly better than I expected considering I prefer anime or cartoon over CG. And its definitely something to see, as a fan, but not a rush. Good times, good laughs, low expectation and it was fun.