I would even say that even "just html" is enough for most website/app. We've been using "just html" at my company ( rosaly.com) for 5 years, we've raised 10 million, have hundreds of customer, and nobody ever complained. And the Android/Ios applications are 234 lines of React-Native which is just embedding a webview , a bit of error screen when there's no internet connection , and intercom library for notification.