not true.
I have picked and been on juries. Each case is different.
You just never know what the lawyers are looking for OR if their “freebie” challenges will be used up before they get to you. The prosecutor may want a white male (despite race not being allowed) and the defense attorney may have used up their preemptions.
In a civil case, one lawyer may want someone who owned his own business or somebody who would be sympathetic to a charge of reverse racism.
That's another of my 'big beefs' with the jury system as currently instituted. The Lawyers have 'way too much power to exclude potential jurors. Voir dire (as currently practiced) is a travesty.