We do all of our bookkeeping in QuickBooks Online (and only QBO) today.

In the US, QBO is still definitely the market leader, and we think there are a bunch of benefits for our customers in using QBO. (Bank integrations and other third-party software integrations tend to be better, there's a bigger ecosystem of e.g. tax and accounting firms that are better-equipped to deal with it, etc.)

(And then from an engineering perspective, we can be a lot more efficient if we can focus on targeting one platform.)