The survival of the Ukrainian state shouldn’t really matter to the people living in other countries, right? So long as civilians are harmed as little as is reasonable in war, it’s just going back to the old ages where monarchs would fight while peasants would do work. We literally already know how Ukraine would be treated under Russia: we can look to Crimea as an example. Crimea is operating basically as you would expect a normal state to operate. The collapse and surrender of the Ukrainian state wouldn’t really impact people’s lives.
In contrast, the collapse of the Gaza Strip would displace millions and lead to mass starvation and disease.