The lead-in to said article:

"For a long time, centering an element within its parent was a surprisingly tricky thing to do. As CSS has evolved, we've been granted more and more tools we can use to solve this problem."

...yeah, but still none of these tools like, actually work?

What about "[...] centering an element within its parent was a surprisingly tricky thing to do. [now...] more tools we can use to solve this", and the subsequent complete lack of a list of these tools that work cross-browser did I miss?