Nope! Bennett is canonically old enough to drink. Also I don't agree with the fandom's interpretation that Scara is as old as they believe due to his obvious physical features and how he acts.

Bennett drinking alcohol was mentioned in a past windbloom event btw! ^^

honestly for me i just lump in scara with the teens of genshin (liyue gang, mondstat gang + collei) different interpretations are totally valid! For me I disregard characters abnormal ages when it comes to characters who aren't human. Seeing how Nahida is a archon and Scara is a puppet their mental+physical age don't directly match with a human's. So, I just go based off information we have in the game based on other characters of the same species.

Seeing how the other archons are much older than Nahida and both look and act like adults I view Nahida as a child! But with Scara seeing how he's a puppet he most likely remains at the age he was built/created and I pair that with his mental age as well. He also matches models with most of the other male teens/young adults in the game which is why I grouped him with the teens. But yeah, it's totally up to you how you interpret his age seeing how ambiguous mihoyo made it. Just felt it would be appropriate to explain my thought process behind this pairing and why I believe its alright! :]