Been a while since I used Aegis, but as far as I remember Aegis is not cross-platform? Aegis you also have to sync the database/file yourself if you want backups of it. So its really down to preferences I guess.

Personally I like having it synced across my many devices for the convenience. I also really enjoy the work Ente is putting into their apps, they're developing solid apps with excellent functionality and releasing updates based on community feedback.