Blowjob is an art that few women are dedicated to with experience. It is not enough to put it in your mouth, suck and move your head as in a penetration. They all do this. The real blowjob should mainly be done with the head still, moving the tongue back and forth, rubbing it under the frenulum, according to an ancient Japanese school. Obviously one can alternate with lateral movements, sucking, making the teeth feel (softly...), but thinking mainly of a still head and movements of the tongue. This is very satisfying for us males, but very tiring for those who do it. I know this from experience, because in one occasion I tried for almost three minutes to consume, with that movement of the tongue, a bite of bread that was too big, which prevented me from opening my mouth further to chew it. :-)
Sorry for translation
i want to give you space for loss of meaning with translation.
That said, a couple of thoughts.
There are some absolute sounding assertions in what you wrote, which may not have been intended, but were there none the less. E.g., no one can accurately state: "They all do this." That is a universal judgement based on individual/subjective experience, it's not evidence as i believe Rigel also points out. Also, as to method, your assertion that "...mainly of a still head and movements of the tongue. This is very satisfying for us males," is also subjective. As a lifetime cock sucker, i can attest that, while there may be similarities, no two Receivers are alike. To me, the essence of either great BJ or HJ is the mutual desire and connection, communication, followed by skill. i'll take lustful sex over skilled sex any day. As a matter of fact, if mutual desire is not there, i'll take a pass. If the man or woman doing the HJ or BJ is not into it, i think a vital element is missing.
As to your comparison of a cock to bread... no lol, no, no, no. Sorry, no comparison no matter how you slice it. Even if it's a baguette. i sort of get what you are trying to say here, but no. There's way to much missing in the comparison for it to be valid me thinks, though this is just my opinion.