Nor should it matter to Russia, because all of this happened not in Russian territory.
Which changed when Donetsk and Lugansk have declared themselves autonomous and asked Russia for assistance against Ukraine's attacks.
That's not how it works. I can't declare my house "autonomous" and ask Putin to liberate it. I mean I could, but that'd be idiotic.
Under international law, Russia is not the aggressor as the "right of self-determination of peoples" is usually held in such high esteem. In my view, the attack came from Ukraine and the 2 republics have asked for "assistance" against a genocide that has been going on for 8 years and intensified in 2022. There is no right of a state to wage war on parts of the former state entity, to murder them and to raze their dwellings to the ground. I assume that exactly at this point the "international law" was massively broken on the part of Ukraine, only... only no one in the West was bothered by it. Pathetic.
There was no genocide. Some thugs commanded by a KGB officer and helped by Russian military took over some cities. DNR/LNR is ruled by a ponzi-scammer Denis Pushilin and his gang of criminals since 2018; the previous wannabe dictators weren't any better either. Following the insurrection in 2014 they were stealing cars from civilians, looting homes, etc - all the usual stuff Russian "military" does. Ukrainians treated them as terrorists and rightfully so.
The conflict was at a stalemate in recent years. It "intensified" when Russia invaded, not before.