There has been some back and forth between Goolag’s countermeasures and Invidious’ countermeasures before arriving at the current situation, Invidious seemingly having lost the battle.

From their git issue tracker:

Hello,

Sad news for everyone. YouTube/Google has patched the latest workaround that we had in order to restore the video playback functionality.

Right now we have no other solutions/fixes. You may be able to get Invidious working on residential IP addresses (like at home) but on datacenter IP addresses Invidious won’t work anymore. (Some datacenter IPs may still work, but that’s a matter of time until they don’t anymore.) … This is not the death of this project. We will still try to find new solutions, but this might take time, months probably.