Right you are Denys: “He who fights and runs away, may live to fight another day!”
Holding territory to force the enemy to expend strength at a disadvantage is a good strategy; giving up territory when this becomes untenable is also a good strategy.
This is what Ukraine is doing in the Lyschansk/Sloviansk area, and it is also what is taking place in Sieverodonetsk.
If you suck them in, you can kill them
That was a mistake by Hitler, he refused to cede an inch. I think he still had divisions in Norway? at the time of surrender?