Your Brand must be:

1. Better
2.  Different/Distinct/Differentiated
3.  A Legacy/Heritage player renovating itself with evolving Culture/Competition
4.  Addressing an Underserved or Unserved Niche
5.  Cheaper

or else it won’t be around for very long.

A few egs to illustrate the framework above.

1.  A Better brand | ‘Mamaearth’ with a ‘Goodness inside’ Promise, ‘Pepsodent’ toothpaste with a 12 Hour Protection promise, Birla Opus paints, Lakme sunscreen | Challenger brands going up directly against the Leader would largely fall in this space
2.  A Differentiated Brand | ‘Pepsi’ with a ‘Youthfulness/Rebellious’ Brand personality, Fortune atta with a ‘Softer roti’ promise
3.  An Agile Legacy/Heritage brand | ‘Parachute’ coconut oil with new age product variants to address evolving Modernity, Sensorial, Performance Needs of younger consumers combined with Packaging graphics updated to reflect Modernity. Combined with Insightful Advertising/Communication.
4.  Addressing Unserved Specialist Niches | Sensodyne toothpaste
5.  Cheaper Brand | Jio mobile network, Campa cola

So ensure your Strategic Brand idea falls in the above spaces, to ensure ‘Brand Longevity’.