Just compensation as determined by who? The government of course. You think most people get what their property is truly worth to them. My mom has been in her house 50 years, raised us kids there, spent 36 of the 37 years she was married to my Dad there. She wouldn't sell for 2 or 3 times what it's worth, why would she want to, her memories are there. She couldn't handle moving, it would probably kill her. Her neighborhood has had a lot of tear downs to build 5,000 sq foot Mcmansions, much bigger than her 2,000 sq foot house and the town would make more in taxes for a larger house. Should she be forced out so some connected developer can make a couple hundred thousand?
It depends.
Can they come to an agreement with your mother? Would not acquiring her house jeopardize an entire new neighborhood improvement and construction project that would employ thousands of people and raise millions in tax revenue that can be used for the betterment of the society as a whole?
It all depends on what side of the argument you fall on. For many or maybe most or even all of her neighbors it might be a Godsend to have their homes purchased at better than market value and start fresh somewhere else. All without the need to hire a realtor or find a willing buyer.
Like I said. Just compensation is a subjective matter.