1. Tour guides navigate for you
Getting your from the airport to your hotel without hiccough. Leading you through the warren of streets in an old town. Taking the lead on a trek so you don't go in a circle. Even just ensuring you find your way out of that enormous botanic garden.
Navigating can include driving you
2. Tour guides do your admin for you
Preordering permits and pre-booking accommodation. Paying admittance fees beforehand, saving you the need to queue. Coordinating travel times for buses, trains, flights, etc. Overseeing the transfer of luggage. Ordering and collecting packed lunches, drinking water and the like.
3. Tour guides keep you safe
You don't go into any dangerous areas. You're not accosted by overly zealous vendors. Your belongings are kept safe. You don't get bamboozled by shysters. You don't pick a poisonous plant, or pet a treacherous animal.
Adventure tour guides are especially important
Set out with the right clobber to protect you from the elements. Stay on path and don't get lost. Don't push yourself too hard (sometimes by monitoring your vitals). Receive timely and appropriate treatment (medical or otherwise) should you need it.
It's impossible to overstate the value of a tour guide in keeping you safe, especially on an adventure trip.
4. Tour guides are interpreters
5. Good tour guides explain things to you
Tour guides have intimate knowledge of the area and can drop all sorts of fabulous knowledge bombs.
6. Good tour guides get you good deals
7. Good tour guides are photographers
8. Good tour guides encourage you
A good tour guide believes in you and knows how to help you to believe in yourself.
9. Good tour guides ensure you miss nothing
This includes seeing animals!
They give you recommendations
10. Good tour guides pivot when necessary
11. Great tour guides celebrate your wins with you
12. Great tour guides can even become friends