Is iPhone 5 still worth buying?

Yes and No. The correct answer depends on you and your priorities.

Yes if

1. You just want the phone to make calls and browse the web
2. You will just install few apps/games
3. You don’t play graphic intensive games
4. You don’t need the latest iOS
5. You don’t need the fingerprint scanner
6. You don’t need 3D touch
7. You don’t need a better camera in the phone
8. You don’t need Apple Pay
9. You don’t want spend a lot
10. You don’t mind reduced or no support/service
11. You don’t do anything that will break the iPhone 5 processor
12. You don’t mind 16 GB as base storage
13. You need a compact phone (iPhone SE is also an option)

No if

1. You want the latest iPhone
2. You want the latest iOS and require further updates for next 4 to 5 years
3. You need a great camera on your phone
4. You play graphic intensive games
5. You need the fingerprint scanner
6. You install a lots of apps/games
7. You need 32 GB as base storage
8. You need Apple Pay
9. You don’t mind spending a lot on the phone
10. You need the latest and greatest processor in your phone
11. You need a phone with large screen