More seriously I think the original cope cages are meant to fool Javalin missiles, which is why it's made fun of because it would be completely ineffective. These and the Russian turtle tanks are meant to be against FPV suicide drones instead which might be somewhat more effective.
Yeah they were attempts to either fool the Javelin's sensor and make it fly too high or serve as improvised spaced armor to reduce the effectiveness of its HEAT round. FPV drones have much smaller HEAT rounds and a lot less kinetic energy so improvised spaced armor may be more effective.
"Cope cages" to describe improvised armor was always propaganda though. US soldiers in Iraq put improvised armor on their humvees to protect against IEDs. In WWII solders piled sandbags and spare tracks on their tanks (you can see many pictures of tanks like this). Field improvised armor is as old as warfare. Often it was not effective. For instance, tank designers in WWII thought that improvised armor reduced the chance of a ricochet, which was a serious problem with the era's AP rounds that saved a lot of tankers. Improvised armor gave the AP round something to "grab ahold of" and aid penetration.
There was video awhile ago about them (suchomimus i thk?). They are effective against small drones (small explosives) while also providing a way for soldiers (of either side) to cope with being in an active warzone. The same things happened in WW2 where tank crews put sandbags, extra tracks and even concrete on their tanks for extra protection even though there was no evidence that it helps and even makes things worse with the extra weight.
Although we definitely mock the Russians for things we applaud Ukraine for, partly because they're the plucky, under-resourced defenders, so field modifications and making do are something to be applauded, while the invading Russian forces should really have the right equipment.
