Technically, it enabled them to go after the Donbass Republics, not Russia. The Donbass Republics are -now- officially part of Russia, but that wasn't the case then.
There are different parties here. One party could be considered the power brokers, armchair warriors who talk of weakening Russia while safely esconced far from Ukraine. The other party could be considered the Ukrainians themselves, who are fighting and dying in large quantities every day in Ukraine. One of these parties wouldn't bat an eye at making another ceasefire deal only to betray it at a moment's notice. I suspect that most Ukrainians themselves, by and large, really do want peace. They are currently being led by what is probably the worst of them, those who don't, and who are now going to kidnapping those who'd rather not fight and putting them on the front lines.
What I'm getting at is that I think that the momentum for a ceasefire is building, not just outside of Ukraine in countries that are most affected by the cutting of crops from the region, but within Ukraine as well. Perhaps most importantly, Russia has already taken much of what could be considered to be the "Russian sympathetic" side of Ukraine. Taking territory further west might not be so hard in the not too distant future as it appears that Ukraine is running out of artillery and just about everything else, but it risks getting into an Afghanistan like situation. I strongly suspect that Russia knows this and is one of the reasons that they were in no hurry to even take Bakhmut, let alone targets further west.