But unlike Fallout 4 there was so much more to the story in Fallout 1 and 2.
In Fallout 1 the quest starts with you looking for the water chip only to find a threat that threatens the remnants of humanity, The Master and his super mutant army. The game then becomes about stopping them.
In Fallout 2 it was similar, Find the GECK to save your people then stop the Enclave that threatens a recovering humanity but the secondary plots involving the politics of the NCR, Vault City and New Reno and their quest for power and the consequences with who you sided with sets itself apart from its predecessor.
I take it you never bothered to play or research deeply into the first 2 Fallouts, haven't you?