I would estimate that Musk accelerated the transition to electric cars by 1-5 years. I believe he claims the same thing you do, that moving to electric is inevitable, and that his strategy has just been to nudge it along a little bit faster.
For a single person, this is still a significant contribution (if we presume that Tesla would not have survivied without him), which just happened to also make him wealthy.
For a single person, this is still a significant contribution (if we presume that Tesla would not have survivied without him), which just happened to also make him wealthy.