Probably inevitable. They bulked up to handle working four rockets through different launch pads at the same time. Now their streamlining those teams to do it faster with less people. It also indicates that falcon 9 is very close to it maximum annual launch rate
Still the same issue as the VASIMR and other ion drives though. At 100kw per N, thats better thrust/kw ratio than the 200kw VASIMR prototype---but to get to mars faster than chemical drives it would need a 5megawatt nuclear reactor to produce the kilowatt-hours to win out. The VASIMR would need a 10MW. Neither technology yet exists for space.
Which isn't to say they can't. For comparison the new A1B reactors powering the Ford-class supercarriers are 700 MW each and they're both 24% smaller and more efficient than the older A4W reactors on the Nimitz class.