The last two Super Bowls were won by QBs in their very first year with a new team. Somehow I don't think Rodgers wanted that pressure.
I think it's more that Rodgers realized he's now the de facto GM of the Packers, considering they lured his favorite quarterbacks coach out of retirement to replace Nathaniel Hackett, they've made it clear they intend to keep his favorite receiver, and they were willing to destroy their salary cap by 2025 in order to give him all the money in the world. Why leave a situation when you have the team management over a barrel?