Agreed. A great mobile website can be much better than a mobile app for many reasons. Supposing most smartphones have browsers that support most of the latest modern web standards, users can access your products/services on all smartphone platforms, not just Android and iOS, but also Windows 10 Mobile, BlackBerry OS, Sailfish, Amazon, Firefox, etc. By being more accessible everywhere, you manage to maintain and grow your user base. Mobile websites can be updated quicker and can still use APIs to optimize use on the platform the user is accessing it from.
There will still be a need for a native app in some cases, but it’s definitely not always needed. There’s also no reason why a company can’t have a great mobile site and offer apps on all major platforms too.