I think this is a good idea, but politicians will find a way to use this concept for corruption, and I envision how will they do it...
Politician 1 will claim an essential need for their family (Obviously not needed) but claimed to be essential, and politicians 2 3 4 and 5 will be his backer that it is essential thus will be approved. And this will go on and on, and by the end they will have high end gadgets, house and lots for their children's, multiple luxary cars, etc.
Well, this won't work. Maybe they will gain some wealth, but they cannot keep it after next elections. Politicians simply cannot buy anything - because they do not have any money. Politicians will be a special kind of servants - they get humble living, some clothes, food to survive...
Ohhh, so all of their assets that they deemed "necessary' will be confiscated after their term? is that how will this work?, so even if the family is living a luxary life while the politician is in position, they will go back after the term ends. Oh nice
But doesn't that will affect their children mentally, and emotionally as their items will be gone without their knowing, thus having issues.
Well, public service in my theory is hard and probably not for everybody. If you want to serve and have family, you will have to count with this. If you raise your children in material way so yes, maybe children can have a problem with that. But I think that it is everybody's choice how he/she raise own children. Maybe lot of public servants (in the meaning of politicians) would decide to not have a family at all.