You are 100% correct and 100% wrong. Before Mint existed, it felt crazy to try to compete against personal finance software. Intuit Quicken, they had a laundry list of features.

Somehow, someone saw a niche that this gigantic tools failed to address.

The beauty of the startup is that if you focus on the right micro-segment (aka a niche), you can grow very quickly and eventually topple the incumbent Goliaths.