It doesn't matter what anyone says not even Obito, once she is alive she's probably going to remain hokage if she was to step down it would be weird for her to do so for someone other than Naruto.
Not to mention kakashi won't have his current powers then. Tsunade is just fine being hokage, people like naruto and co who are stronger can make good military force they don't need to be cooped up in the office.
Tsunade does everything a hokage does well, her fighting might be a bit less than the other thing but she's been doing a fine job.