I don't have faith in true (aka direct) democracy. It relies on the average person being well informed enough about everything involved in running the government to make good decisions. It also relies on every person in the country acting in good faith for the benefit of all, which at best you could convince _most_ people to do _most_ of the time.
I do have faith in representative democracy to do _approximately_ the right thing most of the time, or at least minimise how bad the bad results will be.
In other words, I think people are better at deciding who to trust to run the country than they are at actually running the country. Given that, it should be no surprise that I also think there will be situations where the person trusted to run the country will realise that telling the public the whole truth will be a bad idea, because they are better at interpretting that truth than the public is.
Lying to the public is not (imo) a slippery slope that inevitably makes anyone who goes down it a monster. Polititians can be something other than perfectly honest and actually satan, and in fact they must be. I think a perfectly honest polititian would be a bad thing overall, even beyond the fact that their career wouldn't last very long.
Where on that scale they should be is in the end in the hands of the public, via our democratic vote. Certainly I don't support constant lies and hiding of things the public needs to know. But that isn't what we're discussing here, we're discussing a single lie used for a good cause (though I admit it was probably not the best solution to the problem, it was at least a logical concept: convince people who need masks less to not panic buy masks, leading to more masks for people who need them more).