Close fight but IMO Izzy’s strikes impacted Rob more than vice versa. Whittaker didn’t need to do THAT much more to make it a different story, but he just wasn’t aggressive enough. He needed to be mixing strikes with grappling, not just grappling to gain control and only then look to do damage.
Personally I just think it’s a bad matchup for Whittaker. Izzy is so long (and has the speed and technique to use it) that Whittaker never feels comfortable with the range to commit to good power shots. In the first fight he lunged a lot (basically became Brunson) and predictably got countered. This time he did the opposite.