Yasir Shah did not have a googly. His legspin itself was great, but you cant survive in ODI's with only legspin, you need varieties. The reason why someone like Shadab has survived this long is due to his varieties.
Yasir Shah also takes time to get his line and length correct. His first over is the worst over because he throws in full tosses.
In test he was a great. He took wickets in England. He developed fitness issues as he grew older. If you guys remember the younger days of Yasir Shah, he was an athlete on the field. He would make dives and all. His age is fake, thus he grew older, abit fat, and wasnt able to deliver the require fitness.