To be truthful those extra 8 GB have less performance impact with the vastly improved memory management techniques that were introduced in Yosemite.
I have 16 GB of installed RAM, running 10.11.6. Currently I have Safari open, Mail, Music, 2 small music related apps and a little over 6 GB of RAM are indicated as "Free". Glad to have 16 GB.
On a Mac since 1984. Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.
