Adventurers have the option to scout right now, but they aren't very good at it.
They are not intended to be good at scouting. Advys are not a military auxiliary.
Why not make scouting a skill that can gradually be improved upon?
Because we do not want them to be used as a military auxiliary.
When advys were first implemented, they instantly turned into a real-time, deep-penetration scouting force. They were used by realms to travel with armies, and then on demand move a few regions deep into enemy territory and scout for their realm. The mechanics of advy movement meant they could generate on-demand scouting reports of nearly anywhere without needing to have hired scouts, and without any chance of those scouts getting captured.
That's why the game mechanics were changed so that advys can't see military forces in the region. Anything that
can be militarized
will be militarized.
And when that happens you will find that just about every advy will be arrested on sight by just about every noble.