Is the second game that much heavier than the first?

Hi everyone! I have a potato PC and i downloaded the SR demo on steam, thinking it wouldnt do much but i was curious. Surprisingly, the game worked super well on low graphs, without lags or bugs so i bought the full first game on sale and im loving it! Im almost done with everything there is for me to do in SR1 and i was looking foward to buying SR2 once it went on sale, but when i checked the system requirements it seems i need a stronger PC with better processor and more RAM... Can anyone explain why the second game has more upgraded system requirements? Is it truly a heavier game (i thought it was the same as SR1 but just a new location lol) Also, anyone played SR2 in a potato pc? Did it work as well as the first game? Thank you in advance