Only pressing one key > having to press two keys. A beginner especially might find this two spaces harder to create consistency
If you want smaller tabs, most code editors allow you do adjust tab size
I mean, I can tap my space bar twice in approximately the same time frame it takes me to move my ring finger off of the a key onto tab, press it, and move it back. As I said it, it's just preference, neither is inherently better or worse.
Most code editors do allow you to adjust tab size, but when viewing it outside of that code editor (e.g. on GitHub) it looks bad to me.
Also, when I used to be gung-ho for tabs I used to have to copy paste a tab from notepad into the editor box on the BLF and then ctrl+v every time I wanted to indent. Now I don't even have to think about it.
loving Google Chrome. It literally auto converts tabs to 3 spaces. Highlight that stuff and see.