They do it because coding a large UI project is brutally hard and money doesn't help that much. Building a new UI team is hard, hiring is hard, managing is hard

They do it because coding a large UI project is brutally hard and money doesn't help that much. Building a new UI team is hard, hiring is hard, managing is hard, designing is hard, it's all brutal. Now do that 2-3X in parallel and manage that efficiently and ship new features on time. Couple that with the fact that web devs are much easier to recruit than devs for any native platform and it's easy to see why they don't bother with native. The real choice is (1) be single-platform (Mac only, Windows only, etc) or (2) use a cross-platform UI with Electron being the easiest to adopt.