Yes, CIPS is worth it for the long run; I've seen this myself. I had a colleague who started as just a purchasing officer, finished her CIPS, and became a category manager within 3-4 years. It's not magic, obviously, but when you've got experience along with this certification, recruiters actually take you seriously, especially for UK and Gulf-side jobs.
Just want to be clear about one thing though: if you get the certification and sit back without building commercial experience, it won't do much for you. It's a tool that amplifies your experience, not a replacement for it.
If you want to check salary ranges and demand across different countries, this overview will help you clear your doubts: https://www.certboosters.com/cips/path/cips