A lot of psychological studies are so poorly designed you can ignore the results completely for other reasons and not worry too much about this effect.

Any study that isn't replicated at least a few times, should be called into question.

That goes double or triple for psychology studies where it's not exception to find that less than half of a set of studies can be replicated: https://en.wikipedia.org/wiki/Replication_crisis#Prevalence

No it doesn't, as psychological studies are done using control groups that, if implemented properly, ought to respond equally to any Hawthorne effect.

Regardless, the results are extrapolated to situations with no Hawthorne effect. So still , much of the research holds only when being observed

The Hawthorne effect doesn't necessarily apply to all people, nor does it affect all behaviors.

For example- it's difficult to poll people on some contentious topics. If you ask people, "Are you racist?" they tend to answer that they are not.

This doesn't call into question most or all polls. It just needs to be taken into account when designing and interpreting polls and especially with certain topics. The same applies to psychological research.

Why?