Not necessarily. They included in the article that we could use decentralized contact tracing instead; and, an article arguing against a feature doesn't need an alternative.
If a refrigerator were being released with a microwave, do I really need to provide alternatives to where I could put the microwave instead?
Among other arguments, it argues that contact tracing is a source of mass surveillance. That alone, for the appropriate crowd, is enough reason to not use it. There doesn't need to be an alternative because the alternative is _not having it_.
Just because a bunch of developers ended up wasting their resources on a feature that is a net loss for society doesn't mean that the feature needs to be released.
GACT is decentralized. The article is arguing against decentralized contact tracing.
> a feature that is a net loss for society
The article doesn't even try to make that argument, which is why it is not very good.
Also: as a mathematician, there is lots of value in a counterexample to part of a proof. Just that, even though the final result is true.