The main reason why we decided to create a new mod manager from scratch, rather than to continue on with Nexus Mod Manager is that the latter is based on code written for Oblivion (Oblivion Mod Manager) and Fallout 3 (Fallout Mod Manager) - games that are now over 10 years old. Why did you create Vortex instead of continuing Nexus Mod Manager (NMM)?
The following answers a frequently asked question of why we created Vortex from scratch rather than continuing Nexus Mod Manager.