I prefer using a drawer instead of a modal on mobile for a more native feel. Open-sourcing Vaul meant more feedback, ultimately making the component better and rewarding to see people use it.
Vaul is built on Radix's Dialog primitive for accessibility. Maintaining a similar API to Radix helps in providing a familiar experience for users.
Optimizing drag gesture performance in Vaul was a challenge. Issues arose due to CSS variables causing lag when clicking the drawer became content-heavy with many items.