Before shelter in place I commuted by bike in notoriously hilly San Francisco and biggest concerns was people on cars acting aggressively or having a safe place to lock the bike, not hills.

Electric bikes are also an option that allows more people to ride in a wider range of situations that would otherwise be a limitation, including hilly terrain.

It's not really a requirement. I live in Edinburgh, and cycle to work in a hilly city over icy cobblestones .

Edinburgh is so compact that you can practically walk everywhere. I frequently did when I lived there.

Electric bicycles are a thing.