Radiator Cap Replacement

I'm replacing my coolant for the first time and want to replace my radiator cap too. I'm having trouble finding the best replacement though. My Taco is a '15, 4L V6 AT 4x4.

Based on recommendations here, Stant is a good choice and using their parts selector says to use 10241, which is 13 psi. Amazon also says this part fits.

However, my stock cap has a rating of 108 kPa (15.66 psi). I included a picture.

My question, is that Stant the correct cap or am i asking the wrong question?

I found this thread which doesn't help the issue as it lists both 13 and 16 psi...
Radiator cap leaking AGAIN!

 

here's the Toyota p/n. i just ordered from Salinas Toyota for $12.57.

 

So... why are you replacing the radiator cap? Is this a Toyota thing? Aesthetics? What am I missing here?

 

It more a preventative maintenance thing.
There is much more to a radiator cap than “sealing” the fill port.
It allows pressure to build and vent.
It also allows the ingress and egress of Coolant in to and out of the radiator.
Lots of function packed in the little guy.

https://auto.howstuffworks.com/how-does-radiator-cap-work.htm

 

That's exactly it. I'd prefer to do it when I have time, not when I have to make time and I thought it would be simple. Well after I order it.