The Ukrainian advance in so-called russia remains the funniest thing to happen in this war.
The russians don't seem to really have the means to stop it, despite the group of Ukrainian forces being rather small overall. Biggest estimate I've heard was something like 4000 men? Ridiculously low number. Even if it were ten times that, it'd still be less than what the russians needed to mass in order to achieve one tenth of what the Ukrainians have achieved so far.
How can the russians be so terribly bad? I suppose it's a combination of two factors. The first is surprise; they were convinced the Ukrainians would never attempt something like this, just at most small-scale raids on the border areas. So why prepare for what's not going to happen? This shows that russia really relies on being protected by... NATO. Yep, the guys who keep telling Ukrainians not to attack this or that, not to use weapons against the territory of russia. The russian regime did feel extremely safe and secure from armed incursions on its territory because it knew that NATO would never attack it.
Unfortunately for the russians, Ukraine is not in NATO.
The second factor is greed. The russian regime wanted to go as fast as possible, to grab as much Ukrainian territory as it possibly can by constantly attacking. In doing so, they have massed all of their forces inside occupied Ukrainian territory. And they made a mistake: they tried to create their so-called "sanitary zone" in Kharkiv. As a result, they missed the signs of the Ukrainian concentration of forces in Sumy, thinking of it as the Ukrainians fortifying their border, not as the Ukrainians preparing to strike.
The russian reserves are mostly regular conscripts -- kids who turned 18 and do their military service, and by law are supposed to only be used within russian territory proper. They're poorly trained and they don't have much willingness to fight, so they're pretty bad in a fight. That's how you got scenes like just four Ukrainian soldiers taking prisoners 30+ russian conscripts. If russia wants to stop the Ukrainians, they need to bring in better troops -- that means those that are actually on Ukrainian territory, trying to advance in Donbas, Zaporizhzhia or Kherson. Or to bring back their mercenaries from Africa, which they apparently have already started, especially after getting humiliated by the Tuaregs over there.
