Because baksheesh is embedded in the economic system of Egypt, salaries in many professions only form a basis for further revenue and to actually make ends meet, one is dependent on baksheesh given. This is the case for many people working in tourism and sadly travelers do not realize this anymore...
These are the people who hold the door for you, hand you the toilet paper, the waiter, the staff on the boat, the cleaner, those who work in the kitchen, etc.
For example for a driver or guide on a desert safari who guides you, cooks for you, etc. the baksheesh is 50 LE (about € 5,50) per day.