That is true, but the idea that programmers can use macros to force the compiler to emit optimal code is wrong, too. In the early days of C, that was (almost) true, but those days are over.

In theory, a compiler could uninline common code blocks, including macro calls, into functions to decrease object code size and/or working set size, thus speeding up the program (example: functions f and g with inlined function h each take 2 cache lines; without inlining, each of f, g and h fit a single cache line)

In practice, using an inline function will give the compiler the opportunity to weigh different objectives (code size, execution speed, debuggability, etc) against each other, and do the better thing.