The manna was provided to give the people something to eat. God could have just caused the people not to be hungry but He did not work that way. We are suppose to work to eat. The people had to get out in the morning and pick up just enough manna for the day. It is suppose to be if we don't work we don't eat.
The manna ended when the people got to go into the promise land and could find the abundant food there.
We always take for granted what is there all the time. If we have good health we take it for granted, if we have a good roof over our heads, we take it for granted, and so on. We need to learn to thank God for every little thing we have and to not take anything for granted.
Everything that I have regularly. Pray for me that I will stop taking every day things for granted.