I agree 100%, people should not wait for a savior to come to fix things, only lazy people do that. Both the return of Jesus (peace be upon him) and the presence of Al-Mahdi are just signs of the Hereafter. Our reality should change by our will and intention to be better people. Allah the Almighty said:

“God will not change the status of people until they change the status of themselves”.

Allah the Almighty had set means for life that anyone can use it does not matter if you are a Muslim or not, there is no special treatment to anyone.

Messiah was in relation to the miracle that God gave him. He will wipe on them and they will be healed. It originates form the Arabic verse: masaha

Their importance as I mentioned before is that they are part of the signs of the Day of Judgment.