Who's this guy? Did he design the engine of Wagon R or part of that team?
The owner's manual is written by people who actually engineer the engine.
I can't believe PakWheels is showing such irresponsible behavior in the videos. Also, I strongly disagree with the 0W part of his recommendation. The most wear n tear on the engine occurs on a cold start, not during operating temperature. The operating temperature of the engine remains around 100C no matter what climate it's in.
These days even the bigger turbo engines recommend 0W-20 oils. Modern engines are a lot different than they used to be. Using thick oil thinking it will protect better OR using thicker oil when the mileage gets high are all obsolete concepts.
If you keep using thick oil in these modern engines, they will fail prematurely with time.
Reference video
I highly recommend you to go through this Motor Oil guide on bobtheoilguy.com. It will clear most of the misconceptions that people have in Pakistan regarding engine oils.
https://bobistheoilguy.com/motor-oil-101/
^ This is a 7-page series but worth reading.