I assume, perhaps incorrectly, that phone contact provides the backbone of these tracing programs. If so, call blocking of unknown numbers would likely cripple them. For those notifications that do get through, our exposure to robocalls and scammers makes us too wary to comply.
Reuters
https://www.reuters.com/article/bc-finreg-data-privacy-contact-tracing-idUSKCN24M1NL
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>cripple
This also applies to the current political polling. I have blocked a half-dozen suspected polling firm phone numbers on the home voip system over the last two months.