Keynes has been discredited in recent years, it's odd that you think he's established anything. The Austrians were proven right and recent monetary policy reflects their view - you don't see much discussion of Keynes anymore. If you don't understand Keynes maybe that's why you don't realise that?
To recap Keynes: his core idea was countercyclical monetary policy, i.e. to issue debt (print money) when times are bad and pay down debt (recall money) when times are good.
It sounds good but the Austrians pointed out that there would be two problems in practice:
1. Give governments a nice sounding justification for money printing and they will do it to excess, creating inflation. The Austrians were right: governments cited Keynes when printing money in a recession, and then the "emergency measures" would conveniently never end. The part where you pay down the debt in good times by running a primary surplus would never be respected.
2. Keynes misunderstood the nature and cause of recessions.
Recessions occur when there has been widespread misallocation of resources, usually due to some collective delusion or state mismanagement. The groupthink breaks and people realize that their investments are duds. Credit is withdrawn, investments cease and there's a giant sucking sound as people lose their jobs whilst those who still have money try to figure out what to do next.
Keynes posited that recessions are quasi-natural disasters that just inexplicably happen, and that the fix is for the government to spend money to balance them out. But this isn't the case and so his fix just makes things worse. It may appear to end the recession if all you look at is a handful statistics, but the underlying misallocation still occurred and when governments step in desperate to create employment - any employment - they misallocate resources still further. Like someone taking stimulants to try and delay the end of the party, it works for a while but they get more and more messed up. There's lots of activity but not much is actually useful. Governments don't care though, because all they're trying to do is keep people digging proverbial holes and filling them back up again.
You can drown the signals of a recession by misallocating resources still further, but it's not a good idea.
Keynesianism has worked out in the past 15 years exactly as the Austrians always said it would, and now Austrian economics is back in vogue. The 2008 recession led to the ZIRP years of easy money that never ended, even when the economy was booming. Government debt climbed endlessly. Inflation span out of control and now interest rates have been hiked repeatedly even though the economy was trashed by lockdowns - exactly the moment Keynes said to do the opposite.