It is not just about size.
The ternary operator is an expression (the 3 parts should be expressions,
Condition a Boolean expression, the other two should be of the same type as each other). The type of the ternary expression is the same type as other two expressions.
S = AValue if Condition else AnotherValue
S are expressions,
AnotherValue are r-values,
S is an l-value,
AValue must conform to
AnotherValue must conform to
Condition must be Boolean.
If Then Else is procedural, it should do something. (often referred to as side effects, in the C tradition, where everything is a Function).
if Condition then do Something else do SomethingElse end
If you understand this then the version using ternary is much easier to reason.
Examples shown in generic, human readable, pseudo code (any resemblance to other languages is purely coincidental).