Yes, '?:' is also known as the Elvis operator [1][2]. I sometimes use it in other languages such as Groovy. But I don't use it in C because this happens to be a GCC extension [3][4] and I've often had to compile my C projects with compilers that do not support GCC extensions. The C standard [5] defines the conditional operator as:

  conditional-expression:
    logical-OR-expression
    logical-OR-expression ? expression : conditional-expression

  expression:
    assignment-expression
    expression , assignment-expression

  assignment-expression:
    conditional-expression
    unary-expression assignment-operator assignment-expression

  unary-expression:
    postfix-expression
    ++ unary-expression
    -- unary-expression
    unary-operator cast-expression
    sizeof unary-expression
    sizeof ( type-name )
    alignof ( type-name )

  assignment-operator: one of
    = *= /= %= += -= <<= >>= &= ^= |=

  ... and so on ...

  $ cat foo.c
  int main(void) {
      if () {}
  }

  $ clang -std=c17 -pedantic -Wall -Wextra foo.c && ./a.out
  foo.c:2:9: error: expected expression
      2 |     if () {}
        |         ^
  1 error generated.

  $ cat bar.c
  #include <stdio.h>
  int main(void) {
      printf("%d\n", 0 ?: 99);
      printf("%d\n", 1 ?: 99);
  }

  $ clang -std=c17 bar.c && ./a.out
  99
  1

  $ clang -std=c17 -pedantic bar.c && ./a.out
  bar.c:3:23: warning: use of GNU ?: conditional expression extension, omitting middle operand [-Wgnu-conditional-omitted-operand]
      3 |     printf("%d\n", 0 ?: 99);
        |                       ^
  bar.c:4:23: warning: use of GNU ?: conditional expression extension, omitting middle operand [-Wgnu-conditional-omitted-operand]
      4 |     printf("%d\n", 1 ?: 99);
        |                       ^
  2 warnings generated.
  99
  1

[2] https://groovy-lang.org/operators.html#_elvis_operator

[3] https://gcc.gnu.org/onlinedocs/gcc/Syntax-Extensions.html

[4] https://gcc.gnu.org/onlinedocs/gcc/Conditionals.html

[5] https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3299.pdf