QuickBooks has kind of an ugly UI, particularly on Macs, but its great virtue is that you can very easily find a part-time bookkeeper who will handle it for you.
Unless your startup is finance-oriented, you should spend your time on product and customers, not bookkeeping. No entrepreneur is likely to add much value by doing their own bookkeeping, so you should outsource this to someone who charges by the hour (about $60-65/hour). If you aren't familiar with bookkeeping, it can be a real time sink when you need to be building product and getting customers.
And the chances of a startup going out of business, unfortunately, are much greater than the chances of a startup outgrowing QuickBooks in a hurry.