Actually a lot of it is nicer than russia russia now
Chechnya is the second poorest part of Russia, with the average income being around 1/5 of the Russian average income per capita. The Russian government has made a great fuzz about repairing some part of the destroyed infrastructure, but there are lots of reports how once you leave Grozny, the damage is still visible. That is despite Chechnya having significant oil and gas reserves, comparable to the Arab oil states. But as said before, the profits dont stay in the area.
en.wikipedia.org/wiki/List_of_federal_subjects_of_Russia_by_GDP_per_capita
What you are refering to is an assessment about the Empire of the Soviet Union, which supposedly empoverished itself while its' satellite states in Eastern Europe were much more prosperous. Which is really a myth. While it is true that e.g. the people in Poland or the GDR were more weathly than the Soviets, that had nothing to do with the Soviet Union supposedly keeping its satellites economically afloat (quite the contrary really).
Perhaps the Kremlin could fix that before engaging in costly wars abroad?
Of course he could fix it. That is one of the advantages of being a dictatorship: If you really want to, you can push great infrastructure projects through without any resistance. But Putin has decided to spent 40%+ of his state budget on his war in Ukraine. Priorities.