This to me indicates that it is recruitment companies applying these metrics (3y+, 5y+, 10y+) as a standard for job ads and companies just go with it. I.e. 3y+

This to me indicates that it is recruitment companies applying these metrics (3y+, 5y+, 10y+) as a standard for job ads and companies just go with it. I.e. 3y+ is just a shortcut way to sort CV's, not a requirement.