Why is #define deprecated?

Question

C++ / C#

Scott Myers' book "Using C++ Effectively" gives an example of a bad use of the #define directive: And further what this can lead to:
#define max(a,b) ((a) > (b) ? (a) : (b))

int a = 5, b= 0
max(++a, b);          // a увеличится дважды
max(++a, b+10);    // a увеличится один раз

1. Why does a increase twice in the code?
2. Why are the arguments in the directive enclosed in parentheses?

Answer 1

Because
1. there is no type control
2. there is no scope restriction, such as namespaces.
3. the macro is expanded by substitution at the place of use, i.e. there will be inserted code
((a) > (b) ? (a) : (b)) which will turn into ((++a) > (b+10) ? (++a) : (b+10))
4 .macros are hard to debug
5.an incorrectly written macro will compile to something you don't understand. For example, if you remove the same brackets
as without them, the expression x = max(a, b) + 10 will open; ?
x = a > b ? a : b+10;
for max, most likely, it makes no sense to wrap the parameters in brackets, quite common, although you can probably think of something to break without them. It's just accepted, due to the fact that macros can be inside the expression and how their non-trivial parameters will be revealed there is not clear.
For example

#include <iostream>

#define mymax(a,b) a>b?a:b
#define mul(a,b) a*b

int main() 
{

  std::cout << mymax(5, 10) << std::endl; // Ошибка компиляции
  std::cout << mul(5+5, 10) << std::endl; // Неожиданно на выходе 55, а не 100

  return 0;
}