I was at Google from late 2013 to early 2016, and even then, I would hear 20% time referred to as 120% time [1]. So 20% time hasn't been a de facto practice for about a decade.
That's a great article. To me it makes painful reading because what it means is that some of the most talented engineers are being hired by Google to do just regular enterprise software stuff, but disincentivised to actually do innovation for which they are most able. If they were back in the open market so many great firms could have been founded, which might be the ultimate corporate strategy for Google - to take talent off the market.
[1]: https://qz.com/116196/google-engineers-insist-20-time-is-not...