You're so far down the rabbit hole your probably not going to make it out but let's have a look at this.
What would motivate a government to deny a treatment works, do you think any bribes "big pharma" could pay would make up for the erosion of the tax base from lockdowns and the closing of businesses?
Why would a government spend 10's of thousands looking after covid patients in ICU if a 20 cent pill worked?
Do you really think even a Liberal government would let people die if there was a cheap option to save them and if so what would be their motivation?
Ima play devils advocate here, even though I don't actually believe this...
1. (some) Politicians get lobbied unethically and illegally and accept kickbacks all the time. The US is more rife with this, particularly the right wing, needing to keep big donors happy. You do what's right for them, you get the personal perks, and after leaving office, they take you in for a job that pays REAL money. (US tax cuts for the wealthy and mining/logging/oil companies destroying the planet but raking in the money, anyone?)
In the end, the economy, the environment, peoples welfare and health don't really matter to someone who has got their cut an aren't personally impacted.
2. Jesus. The religious base of the LNP don't think anyone but God can cause/cure covid any more than they think humans can effect the climate. God will sort it out.
3. Other stuff
A government is just people. People are greedy, selfish and fallible....particularly the demographic that is attracted to the power that being in politics brings.
As I say, I don't believe all that, I'm more optimistic and trusting of (most) government than I probably should be. I wholeheartedly blame social media for the ability to spread and compound misinformation, and remain totally unaccountable for it.