Someone else explained this really well in comments in another post. I believe they said something like 'They keep updating sanctions over time to maximize impact, basically after a while when Russia gets uhm what's the right word 'comfortable?' with certain sanctions they will add new ones on other important things to impact as much damage as possible to their economy.' Basically the idea is dealing much more damage over a long period of time than can be done at once.
Dikai t1_ja13g57 wrote
Reply to comment by sudocitrus in EU slaps sanctions on top Russia officials, banks, trade by BrandYearg525
Someone else explained this really well in comments in another post. I believe they said something like 'They keep updating sanctions over time to maximize impact, basically after a while when Russia gets uhm what's the right word 'comfortable?' with certain sanctions they will add new ones on other important things to impact as much damage as possible to their economy.' Basically the idea is dealing much more damage over a long period of time than can be done at once.