Blueshy

I thought of something similar the other day but in a slightly different way. Instead of doing anything based off age just have professionals with perks.

The Engineer: Can repair things with a 50% reduction in tool condition loss, can create arrowheads out of tin cans but the arrows have low durability (regular arrows but they are created at 20% durability), tools last 30% longer. Starts with repair 75% maxed out.

The Outdoorsman: Fishing and Rifles start at 4, all animals detection radius 30% smaller and can only have up to two fragrance, creates 4 lines per cured gut.

The Tailor: Can repair clothing 30% faster and starts out at rank 4, sewing kits and fishing hooks last 50% longer, can create clothing from animal hides 30% faster, can cure hides 50% faster.

The Athlete: Can run 50% longer and 20% faster, requires 15% less sleep, requires 10% less calories.

Those are just an example of some classes. But I really like the idea of having certain perks you can choose, perhaps just the perks themselves without any skill buffs to make it simpler.