I commuted for years on my bike through rain. For me, there are only two answers and my decision depended on the temperature:
1. Keep my legs dry with gore-tex pants over bibs.
2. Just bibs and ride with wet legs.

The most annoying part of option 2 is wet socks. With option 1, I would wear gore tex overshoes. On shorter rides, I would just put my feet into grocery bags before putting on my shoes. Waterproof with zero breathability.