As title says. Some companies have reserve resources or prepaid yearlong subscriptions, so it might be hard for them to have a secondary/redundant infrastructure cost.
I have already read that pluggin in to your own AWS resources is on the roadmap, thats amazing. But if you want to beat everyone in the field, and be trully "just write code and leave the rest to us", then supporting other major cloud providers in the mid term might be a good bet.
I'm thinking of at least Google Cloud and Azure.
I'm pretty sure this is something that you guys already thought about, but I had to leave my feedback anyway :)