The lack of a large and mature ecosystem would prevent me for starting a "large" web project. Svelte is still missing UI frameworks like Material UI or Vuetify. Won't you need date range picker ? Full powered data-tables ? Treeview ? Advanced cards or other layouts ? Awesome effects / styles for a rich UI ? Svelte Material UI is a start : https://sveltematerialui.com/ But I will definitely give Svelte a try for my next "medium" size project.