I think the general consensus is that it's elven society that considers 100 the age of maturity. Elves grow to adulthood at the same rate as humans, but the knowledge and worldly experience they must gain is what elves see as being an adult.

So, a 73 year old elf would be more than able to drink responsibly

Except if this was how it worked, then elves would be babies for like 10 years before being toddlers for like 30 and teenagers for 50-70 years.

A decade as a toddler? Nah.

I think it's fair to say elves reach maturity almost as quickly, just age slower after reaching maturity. Same with dwarves, etc.

Just gonna point out, like I did the last time this comic was posted, that she's wearing a hoodie and holding a smartphone. This isn't a medievalish world.