I don't think it's a hoax but I can see why people might do.
For a start, there are a lot of undercurrents of things that are unfair, discriminatory, or hypocritical in political life, and social life. Some of these things are spoken about, some are not. I think life experiences dictate how much people notice this stuff - you notice more if marginalised, even if you can't put it into words. But it primes you to believe that things aren't quite right and then people latch onto conspirary theories...
Secondly, this whole situation is WEIRD. We've very quickly had to adapt to a "new normal", a lot of which goes against basic social behaviour, that we've learned from birth, as well as natural instincts. So people will be unsettled on a really deep level, it's frightening, beyond conscious reason.
Thirdly, the way people are treating the virus and politicians are dealing with it doesn't add up. I don't think a virus that kills 1% of the populaion can really be called a "deadly" virus, in terms of the everyday understanding of that word. So it's easy to think it's being exaggerated. Also the keenness of politicians to lockdown the population yet still not have a grip on borders, and to get people back to work but you're still not supposed to hug your mum... it feels very dystopian. I mean, fgs, we're living in a society where it is illegal to enter each other's homes! (That's fucking massive! It overwhelmes me if I stop to think about it.) Where people will be able to go to a restaurant for dinner but not a friend's house, all sat at their distanced tables, viewing others as potenitally contaminated... where people can only meet in the open (again, this is probably largely felt at the subconscious level, to do with privacy). Not to mention the hypocrisy of politicians not obeying the rules, so it might be easier to think they know something we don't... It's a mess of conflicting information that's potentially satisfying to solve with a conspiracy theory.
Disclaimer: I agree with lockdown and don't think it's a massive hoax, but am questioning some of the measures and think the harm of lockdown in some cases outweighs the risk so rules should be modified. I also understand the need to get the economy moving, even though instinctually it feels wrong.