Now…actually thinking about it, there are some games that allow to save a checkpoint but they only load if we die, on otherhand Mecha Ace if i remember has a restore function from stats menu
So yes actually saving is possible w/o DLC, its just depends on the writer if he/she wants to implement the save options.
But then again small stories dont actually need saving but the big ones with multiple branching can use some saving, ya know…saves a lot of time on scrolling through the whole story again.
But then a question arises “does it kill the replay value?” well sort of
Imagine you save the game on a crucial point the Choice A lead to good end and B leads to 'meh’
So you get the good end, get some achievements and before hitting the “end” button you load to choice B and get the hell of ending and other achievements, so yeah saving kills replay, but sometimes youll have to start over again for certain choices
all i can say is, there are some games which can use save feature but others dont require it at all.