With 24GB, I rarely needed it all, but a good portion was cache/buffer, I.e. 10GB. Of course you can just swap to SSD and get pretty much the same performance, until you don't..

I have 16GB, I haven't done much today, I use Safari with 7 tabs and have Spotify and GitHub Desktop open.

Memory used: 10GB

Uptime: 1d

I don't know, feels like OP is right. 16GB is not enough in 2021, especially since I my computer is from 2013 and already had 16GB.

Unfortunately this is where Apple decided to make money, so we have brand-new 8GB $1000 devices in 2021. Thanks Apple.