For the task of keeping money in an economically useful state over time? Generally the government, but it depends on the country.
Banks have a profit motive and therefore keep trying to do things which value instant reward over stability.
Governments (when not corrupt) are motivated by the actual success of the nation as a whole rather than individual sectors. They mostly only need to care about short-term wins for elections.
Yeah, Turkey is pretty much a go to case for "Don't trust the government, trust the central bank".
What Erdogan should do is to support the agriculture sector and help it provide enough food for everyone.
By forcibly lowering interest rates he is actually cutting off financing for the most productive companies. High interest rates are supposed to drive out unproductive companies and make it harder for them to acquire financing.
If the agriculture sector is highly productive (indicated by rising food prices) then it will automatically obtain more funding and other companies will have to downsize, which makes more resources and workers available to agriculture companies.
Neither. That is why cryptocurrencies were created. 2008 Mortgage crisis blow-up mortgages stole citizen's money in bank accounts (deposit custodial accounts). The bailout was to hide/replace this money.
Citizens don't trust private banks. They don't trust the government since congress sells out to lobbyists.