Well, you could definitely do policies like that in a plain democracy or republic without any guaranteed rights of the citizens. In our particular constitutional systems, and many others, the founding documents say that the government can't do certain things, even if they pass a law saying they can. (Of course, the Constitution can be amended to remove rights, but there is an intentionally high bar to meet in order to do that.)

Congress could pass a law tomorrow, or California could pass a ballot measure with a 100% Yes vote, saying (for instance) that some random company now belongs to the government, or to Gavin Newsom personally, or to me, but the courts would still be obligated to strike it down since that grossly violates the Seventh Amendment. Ideas like this are commonly referred to as being checks against "mob rule" - the system recognizes that 'what the people want' isn't necessarily supreme when it runs up against other people's recognized rights.