IMHO the biggest problem in this area is not letting insolvent banks to bust. As you said in order to make money banks have to lend money. When you "have" to grow your earnings every year it is very easy to start lending money to insolvent customers and when you know, that there's always will be tax payers money to save you, you lend to less and less solvent clients as time passes... And you do that with ease...
What central banks do is beyond insane... The next recession is around the corner. There will be a lot of fireworks! I wonder how will cryptos performance will look like, when bonds and stocks will be in freefall simultaneously. Interesting times...