Most people keep saying how if we'll hit a recession or major economic downturn, the government-backed currencies will crash and BTC and ETH will moon.

If most people consider crypto risky and super volatile, then the first thing most people will do, in a situation like that, is to get rid of it to use their money for more basic needs like food, shelter and more immediate needs, rather than keep it in crypto. This will most certainly lead to a price crash.

Since crypto wasn't involved in 2008, it's really hard to say. considering a lot of people have money tied up in stocks/bonds/real estate, I would think they would hunker down and ride it out, not wanting to risk more money on something like cryptocurrency. Wouldn't this make the value go down since not much new money is coming in?

I honestly hope we do not see a big recession again for a long time, and would much rather see the adoption of crypto push the value up steadily over the next 5-10 years.

Gold went from around 1000 to 730 in 2008 when the crash occurred, likely because people needed cash. After that, it started to rise again but a lot of other factors were intertwined.

Endless QE, the Euro crisis, the robbery of savers in Cyprus setting an ugly precedent for the EU etc. Super complex, but long story short my guess would be an initial dump, and if faith in fiat has died globally, yes a crypto/digital money of some sort will rise. That, however, will be a nightmare scenario.