Because Russia realizes that this proxy war can escalate into a real war with NATO, and they’re obviously going to save their best weapons for that.
Meanwhile, the whole war was sold as a special military operation in Russia, meaning that Russia is not on a war footing and life for a typical person in Russia hasn’t actually changed all that much. This is basically equivalent to when US went to destroy Iraq, and most people in US didn’t really connect the war with their day to day lives.
Russian economy is currently growing at 4.9% as even western publications admit, they’ve managed to reorient their trade towards the east. On the other hand, many western countries are entering recession now, and there’s massive political unrest all over Europe.
You don’t have to be high on Russian propaganda to know this because all of this is freely admitted in western media. The fact that you don’t understand any of this shows just how ignorant you are regarding the topic you’re attempting to debate here.