Well we knew that their use was rather limited
However, at least in Germany they actually have turned into a beacon of hope, but not in the way one would expect.
The German tracing app CWA (Corona Warn App), not only followed the minimal standards you would expect, like having public source code for the app, no they have public source code for all components including public documentation on the rationale behind the scheme they used.
And the design was very decent trying to keep the advantages without compromising privacy. Essentially it was done in a way you only had to expose yourself when you got tested positive.
Now the main point of criticism was that it was hugely expensive... until the Luca App came along which claimed to do the same thing, but was developed a lot less competently yet charged a similar amount. While the CWA people actively engaged with the security community, for example by giving talks at hacker conferences, the Luca people only complained that people were complaining about basic defects of it.
