Putin will not accept a ceasefire under the current conditions because it does not address the root causes of the conflict. It does not remove the threat of Ukraine/NATO doing something stupid in the next 5-10 years and causing an even more serious & damaging conflict than the current one. It also does not meet the stated Russian demands of demilitarization, denazification, and no NATO membership for the Ukraine.
On the strategic level, Russia is taking losses, however, they're also inflicting far greater losses on the Ukrainians. They believe their own losses are acceptable and can be sustained until the goals of the special military operation are met, even if they have to kill every last Ukrainian along with anyone in Europe who's dumb enough to get involved. Given that they've already destroyed more tanks, artillery, and air defence systems in Ukraine than the entire EU put together has in its inventory, they're probably right. The US Army War College published an article a couple years ago where
they admit the US/NATO would take massive casualties if they tried to fight the Russians, you can read the article in the link but in short they estimate around 3600 casualties/day and 50,000 or so in just 2 weeks. Given the advancements in drone technologies & tactics since then, the casualty rate for NATO will be significantly higher today than the estimate from 2 years ago.
As for accepting vs. rejecting a ceasefire, this gets interesting. If you go by the Western media narrative where Russia is suffering massive casualties with its economy on the brink of collapse, then it makes sense for Russia to seek a ceasefire to recover & rearm for round 2. However, the Western media narrative on the Russo-Ukrainian war is just as bullshit as their reporting on Israel's wars vs. Palestine and Iran. Reality is the Russian economy is doing just fine and their actual casualties are far lower than what our media claims. In this case the logical choice is to continue the war until Ukraine unconditionally surrenders and accepts whatever terms Russia demands, this also has the further benefit of continuing to impoverish, destabilize, and de-industrialize Europe which reduces the potential damage it can do in the future should it choose to declare war.