Plus it's simply ineffective. Enough people saw through the lies such that all the masks sold out anyway. I reckon an honest approach and appeal to morality would have seen more masks donated to hospitals than simply telling people that they don't work.

That's a fair point, although in this case drawing attention to the shortage would have made it even more newsworthy, and might have made the few greedy profiteers more fervent in their desire to buy up all stock, even as the average person reduced their buying. Appealing to morality works better when each person gets an approximately equal vote. If one arsehole can counteract the good behaviour of 10, that weakens the honest approach.

Whether it would have actually been worse or better I can't really guess, but I do see your point that it might have worked and definitely wouldn't have weakened public trust the way the dishonest approach did, so yeah, I'll concede that was probably a bad call.

Not only distrust of politicians. I'd say the mainstream media have suffered from a similar loss of trust over the last years because most outlets simply repeat official guidance from the WHO or national agencies.

100%. And for me personally, I think the most powerful discrediting tool is juxtaposition of their changing positions.

It’s very common to see “super cuts“ of the media pulling a complete 180 on positions. Those are super compelling to the public, who are generally in alignment in hating hypocrisy.