Looking at the links and white paper, this is really related to Ransomware and Defender only. In that regard, they are certainly getting better, which then makes it an easy marketing statement to make. But everyone is (generally) getting better over time. Reading between the lines, what this is really saying is that Windows Defender is most likely Good Enough for most home users, and realistically it probably is. Most signature based software is terrible and has a 40-something% efficacy rating. The free AV has been shown to be untrustworthy with adware or selling data or various unsavory activities.
Compared to enterprise/corporate options, it's really not a worthy comparison unless you have to implement it for compliance reasons. Some corporate solutions are not considered AV in the compliance sense, even if they perform the same role. And if you really are a geek and like to have better control this won't be what you want either. There are a lot of caveats in their claim, but it makes headlines.