Even after I heat and oil, why does food stick to my stainless steel pan? I've had this pan for 8 years. It's low priced and average — I see no brands or names on it — not even on the bottom!  I followed What’s the Difference Between Nonstick and Stainless Steel Cookware?

So here’s the crazy thing: stainless steel pans can be nonstick, if you’re doing it right. If you heat up your pan with oil or butter until it’s hot enough  then add your food, things will not stick. Stainless steel pans can withstand really high temperatures, so you can sear and brown things like meat in them, and you can also add water to the pan to deglaze the brown bits from the bottom and create a delicious sauce.

and How to Turn a Stainless Steel Skillet into a Nonstick Pan | Epicurious

You can season a stainless steel pan and make it more or less nonstick. Here's how:
Heat a stainless steel skillet over medium or medium-high for 2 minutes. Add enough vegetable oil to coat the entire bottom of the pan with a ⅛ inch of oil. Heat the oil until wisps of smoking begin to appear, about 6 minutes. When the oil begins to smoke, remove the skillet from the heat and cool the oil completely. Once the pan has cooled, pour out the excess oil and wipe up the remaining oil in the skillet using a paper towel. You want a glossy sheen left in the base of the pan—that's your nonstick surface.

Question 1
Please see pictures below. Please approve my pictures?  Can you confirm  if this is stainless steel?
Question 2
If it is, then why does food stick to it? I tried to — separately — home fry potatoes, stir fry rice, boil pasta with filtered water. The potatoes rice, pasta all stuck to the bottom of the pan!
I thought that all stainless steel pans were non stick? Was I wrong? Do some stainless steel pans stick? If so, how can I deduce which stainless steel pans are non stick? I'm thinking of buying a new brand name, high quality NON STICK stainless steel pan!
https://i.imgur.com/xtiKrxz.jpg
https://i.imgur.com/GlBFLOa.jpg
https://i.imgur.com/hw9f5cO.jpg
Stainless steel pans are not non-stick by default, since they don't have a non-stick surface/coating.
You can recognize a non-stick pan by the non-stick coating on the inside of it. (It's usually Teflon (a black coating), but there's also things like ceramic)
As far as your pan goes, it looks like a plain stainless steel pan to me, no coating to make it non-stick.