goverment stack?

guys how it when you change goverment buff from other one don't gone?

for example, I had technocracy with stone mile 3 on, changed to oligarchy and still got buff from technocracy milestones (+2 stat buff), when I changed goverment this stat stayed, when I change from technocracy to oligarchy I keep technocracy computers on planet 

so who stop me take god machine from technocracy and change to oligarchy for free corp links or to empire to get buff from vassals and decrects (I know god machine buffs are that massive that you don't need corp links, but I nerfed it by 95% , f god machine give me now only 50% research, 50% prduction, +100 money, 20% capacity and +10 moves)

but when I change from oligarchy to other goverment I lost all my corp link

you can also change goverment from empire to other to get back control from vassal planet rebuild good staff there and pick empire again  

and question in end, why empire don't have any scientists expects in council? they got only 2 research from 50% research bufs and lack 1 random tech slot

I had to balance it myself cause god machine was just ridiculas, oligarchy was too weak, empire was ok and federation is just worst version of empire, why do even use federation when you can use empire?