A war is not raging between two very poor countries. A war is raging between NATO and Russia. Russia, despite recent setbacks, is holding its own. The US has sent roughly the same amount of support to Ukraine this year as Russia spends on its entire military for a year. And yet Russia is still holding its own. Every country in NATO is supporting Ukraine with weapons and/or supplies, and yet Russia is still holding its own.

No doubt Russia is suffering. No doubt Russia underestimated how difficult it would be to get a negotiated peace. But also no doubt the 100k+ troops Russia sent in was a small fraction of the number of Ukrainian defenders (plus Western "advisors").

Standard military math says a successful attacker needs 3x the number of defenders. After 7 months of fighting, Russia occupies about 20% of Ukraine with 1/3 the troops. Say what you will, Russia has had A LOT of success so far with far fewer troops.

Only time will tell if recent Russian setbacks are temporary, or the start of a trend. Note that the setbacks are limited mostly to the area around Kharkov, which is not a stated primary objective of Russia. Russia is still advancing in / around Bakhmut, which IS a primary objective of theirs.