Unicode fonts (like Iskoola Pota) are used for the web and emails because they are "readable" by any device. Mi Nelum 98 is a decorative font where the computer sees English characters but displays Sinhala shapes.
In the landscape of Sri Lankan design, fonts like Mi Nelum 98 are more than just software; they are "cultural infrastructure". While modern Unicode fonts like Abhaya Libre Noto Sans Sinhala Mi Nelum 98 Sinhala Font Free -FREE- Download