I think we might under-estimate the impact that playing on the PGA has on family life. There are over 40 tournaments on the PGA Tour, and members have to play a minimum of 15 plus some players (like Rahm) now have to play in each event at least once every 4 years. Most members play between 20 - 30 tournaments per year. If you have a young family (like Jon Rahm does), that is a lot of time spent away from your kids at home.
By contrast, the LIV golf season is 12 tournaments (one or two per month from Feb to Aug), plus some players could play in a few majors if they qualify.
I don't know if that had an impact on Jon's decision, but I wouldn't be surprised if it was a factor.