Alright, we're getting closer...
Most sporting competition favors the more offensive team. Everything else being equal, a team that is able to score more is ranked higher than the one that scores less because to win, you have to be able to score.
Since both teams are tied in records and points differential, they obviously have been able to score... To be able to win, you also have to be able to play defense. If you have no guys playing defense, the other team scores every time. To be able to win, you also have to be able to rebound. Otherwise, the other team just keeps shooting and getting offensive rebounds until they score.
Again, basketball is not a shooting competition. No scoring = automatic loss. No defense = automatic loss. No rebounding = automatic loss, etc.
Total points is just a boxscore stat like total rebounds. It doesn't mean anything other than the fact that one team is more offensively focused, and the other is more defensively focused. Or, one team plays at a faster pace, and the other plays at a slower pace. Or, one team has played more OT games than another team.
And I did not say H2H was perfect. I also suggested a couple other options which are reasonable. H2H is just an example of a "more-reasonable" option than total points.