It's still difficult because the Web experience also sucks. Sliding off-screen menus, maps navigation (this is very handy for finding Airbnbs/hotels closer to your activities), gestures, dynamic charts, etc, those are examples of features that are very poorly implemented with mainstream Web technologies, creating a frustrating experience for the end-user.

Even though I hate it, can see why those "simple" apps exists: the Web still feels somewhat hostile to phones. Unless we create an alternative for the scrolling-page-point-and-click DOM[1], mobile will continue to be a second-class citizen in the Web.

[1] There's WASM, but I'm not sure if the performance will ever match native UI rendering implementations. Or Google would had implemented Flutter in WASM from day one.