Yes, if you're only solving for "not Earth" then Mars is good match. But if your only goal is to leave Earth, why not move to the Moon? It's much more practical.
Without a plan to make Mars more habitable for humans, Mars will be a lot like ISS or Antartica: a place where a small number of lucky scientists go for a few months before returning home.
The moon is only more practical in terms of distance/travel time. In every other way, the moon is drastically more inhospitable than even the worst day on Mars, so anything gained by the shorter distance is quickly nullified by the difficulty of existing there.
If the issues surrounding transit can be addressed, Mars is by far a superior target for colonization.
Terraforming Mars is an undertaking that may well be beyond humanity, but it doesn't have to be the whole planet to make it effective (though that would be the safest).
As far as I understand the Moon has no water which makes it far less suited for colonization than Mars, even if the Moon is closer. Also Mars has atmosphere and it's surface temperatures are less extreme than the Moon's.
Without a plan to make Mars more habitable for humans, Mars will be a lot like ISS or Antartica: a place where a small number of lucky scientists go for a few months before returning home.