Sure. This is true and a problem.
Unfortunately, there a major practical problem. Russia is squatting on a large chunk of Ukraine's territory and grinding out a very slow advance over more. Russia will not be evicted unless someone very substantial (the USA or Europe) commits a military force in support of Ukraine. Russia is not going to give up anything it has easily, because it's winning - even if incredibly slowly and expensively.
So what's it to be? Commit troops in support of Ukraine, or a peace treaty?
A peace treaty is effectively going to have to be a compromise. A compromise looks very much like it will have to involve Ukraine permanently conceding territory, and at minimum that's going to be Crimea. It might be able to fudge an acceptance of the status quo for the other four oblasts in partial occupation, without formally ceding them.
As a repudiation of the UN principle that countries should not take territory by force, Ukraine ceding land is appalling. On the other hand, what better option is genuinely available?
Ukraine can reasonably argue that ceding land would not represent a solution at all, unless accompanied by real guarantees-- emboldened by success, Russia would inevitably invade again in a few years. It's what they did last time they were allowed to seize territory. And the time before that.
Option one would be for Ukraine's backers to pursue economic isolation of Russia alongside the military assistance they need to defend themselves. So far the material assistance they've provided to Ukraine has been insufficient and late, and the economic isolation of Russia has been staggered and half-assed, all while still funnelling billions to Russia for their oil addiction.
Option two would be a defensive pact between Ukraine and other Eastern European countries that are threatened by Russia-- separately from NATO.
Option three would be a cessation of hostilities allowing Russia to hold some chunk of the territory but without legally recognising its ownership, with a view to regaining it through diplomatic means in future. Similar to the status of Crimea from 2014 to 2022, or Transnistria, or Abkhazia.