Why do people quit budget apps?

The two biggest barriers to tracking money, as I see it: connecting a bank account and typing in every receipt. So Xpense does neither. Receipts are scanned on your device and there's no bank to connect. The trade-off: nothing is pulled in automatically. It has monthly and category budgets, spending analysis, recurring transactions, subscription tracking and iCloud sync. I'm building it solo and want to know what's missing. Two questions: what made you quit your last budget app, and what's the one thing you'd add?