I thought so too, it's a part I've always struggled with effectively using, cause I get lost so quickly so was happy for a moment. But then reading the comments first, I got disappointed before I even had a chance to open the article.
I find it impossible to use without a plugin. I use https://github.com/mbbill/undotree and map it to `U` since I realized I never use `U` and it's easy to remember. https://github.com/sjl/gundo.vim/ is also popular but I like that the former is in pure vimscript (and the interface is a lil' better IMO).