Great news of him signing a new contract.
I always found it strange that people see this as 'lack of ambition'. True he might be able to win more trophies elsewhere and I'm sure that many footballers will measure their career by their trophy cabinet at the end. But who remembers all the (part-time) players of the first Chelsea title under Abramovich? They'll have a decent trophy case, I'm sure.
Jack has the opportunity to become a villa legend, if not THE villa legend, should he play his entire career at Villa. Even if he doens't win anythings, Villa fans will love him forever. I'm sure many teenagers of today would tell their children in a few decades about the times they went to Villa park 'to see grealish play'. It seems like choosing to be remembered by many people (global fan base) who know your name, but aren't sure when exactly you played or being remembered by a few (Villa supporters, not too few I know) like a superstar until he's old, buying him a beer 'for that goal against SHA after taking a punch' in pretty much every pub in Birmingham. Someone mentioned Shearer at Newcastle, let's hope Jack does the same.
(I know Gabby only played for us and is our club top scorer, but his last few years weren't really any good, so there is no comparison)