That is the way to prolong the war and nothing about it is normal.
The only way to stop an invading force is to hit them where it hurts which is hitting Russian infrastructure on Russian soil.
Look at any other invasion in the history, they never end by fighting the war in the invaded territory. WW2 didn't end because Nazis were defeated in the front-lines kilometers outside Germany or for example the invasion of Yemen stopped the day the armed forces of Yemen managed to attack their invaders' infrastructure inside their own soil (eg. Aramco in Saudi Arabia, UAE airbases and US military bases in the region, etc.).
Of course that is not something that United States would ever allow Ukraine to do which is why they never send any strategically important weapons (eg. MBMs and LBMs) to Ukraine.
If Ukraine uses ballistic missiles to target Russian infrastructural facilities, then the latter in all probability will retaliate with nuclear strikes. And that will trigger a new world war, where no one is going to win. Even if NATO manages to nuke 90% of Russia's territory, the Russians will destroy NATO with nuclear weapons from the remaining part of their land. As of now, Russia has 5977 active nuclear weapons. They have some of the best ICBMs in the world. I guess they need less than 1% of that number to completely annihilate any life form from this planet.
In the end, if a nuclear war happens by any chance, then no one will win. All forms of life will be wiped off.