1. It's so cheap and you can afford it. (Even those who can't afford it still need life insurance, I'm just saying it's even more obvious for you.)
2. The idea is to become self-insured in the sense that you have enough assets that your family would be 100% taken care of without you. I don't think that's the case given what you described and given all the expenses that are coming your way as your kids get older.
As a separate point, you should also get life insurance on your wife. Maybe $500k. It's also very cheap. The purpose would be to cover childcare and other expenses you would incur should she pass away.