No one believes that mars is going to be a better/easier place to live than earth. It's idiotic, and only spouted by people that don't like the idea of Mars, and said to make "marsers" look like idiots in association.
The chief value of Mars has two parts. First, it opens up the first true frontier we’ve had in over a century and could serve as a sort of societal pressure relief valve. Second, as soon as there’s people living on Mars the impetus for developing technology to make living there (and in space) more safe, sustainable, and comfortable increases dramatically, which is a critical step in achieving true mastery of human spaceflight and ensuring that the species is not forever stuck in the bottom of Earth’s gravity well.
Some may argue that the moon can serve these purposes as well and that may be true to a degree, but its proximity is a liability. Moon inhabitations are close enough to be well within the sphere of Earth’s political influence even if it achieves self-sustainability, which itself is unlikely because Earth is always there as a convenient source of supplies and escape hatch, just a week away. There’s a certain level of necessary commitment and autonomy that comes with building a civilization on Mars which I believe is key.