Universal power supply for PCs, setting voltage

I probably don't need a universal auto power supply, but otoh, if I'd
bought one for the last laptop, I wouldn't to spend 30 or so dollars for
another one now. 

Some of them have 3 wires connecting the tips, one to tell the power
supply what voltage to provide, I assume, but others have only 2.  How
can that be satisfactory. 

This one, for example.  
https://www.amazon.com/HKY-Universal-Notebook-Computer-Smartphone/dp/B0BZGSMLMP/ref=sr_1_1_sspa
See the first picture.  But it's $44, one of the most expensive.  How
could it not work right? 



https://www.amazon.com/Belker-Universal-Adapter-Charger-Toshiba/dp/B08LKXDBX3/ref=sr_1_1_sspa
Smaller than most.  Are they just trying to trade off the name Belkin? 

At first I thought it had to be good because it was Belker, but when
writing this post, I remembered that it's Belkin that has a reputation,
not Belker.  !!  

2)  Some have 50W, 65W or even 100W.   What could need 100W?   I
currently have a Dell Latituded 5510 (not the other Dell 5510).  Surely
65 w is enough or even 50. ????