Guess that depends on where you are. Many places in the world have very high social mobility along with solid welfare and pension systems.

Maybe somewhat less that 40 years ago, but certainly much better than the last thousand years overall.

Intelligence is working out that you don't have to struggle. UK example, don't move to London "for the jobs" if you are only finding minimum wage work.

Success looks different for different groups of people, unfortunately. A slave could be considered more successful than another, while remaining a slave.