If 4 did not exist, then you would be using a base-4 quarternary numbering system (which is able to use the numbers 0,1,2,3)
The system will be similar to how our base 10 numbers work, but instead of counting to 9 before adding a trailing zero and becoming 10, you would count to 3. So 2 plus 2 would roll past 3, and equal 10.
Technically a base 1 system cannot exist (effectively), because it would mean you were counting from zero (nothing). All base systems for real "math" have to index from null. You couldn't even count using 0, 00, 000, 0000 because how would you know if the first 0 indicated actually zero, or was it the first item? You could only identify it by the absence of all marks, which doesn't work in math or any modern setting.
You’ve inadvertently hit on the beginnings of an apparent paradox to do with the relationship between numbers and the counting numbers
Suppose the largest number you can have is X and the smallest number you can have is -Y. Then between -Y and X, you can count X+Y numbers which is clearly larger than X. But X is the largest possible number so X+Y doesn’t exist.
Gotta stop you right there. A largest number doesn't and can't exist. If we introduce one, paradoxes arise all over the place and the whole system falls apart.
Oh so that's why big brother is telling everyone that 2+2=5 man if only the administry of truth did a better job at explaining his conclusions we wouldn't have a need to re educate people