Mostly that's actually indeed the case, because of how statistical agencies define employment. People who are so terrible at work that they can't get a job anywhere eventually give up looking and fall out of the workforce entirely, so don't count as unemployed anymore (arguably they should).

For the rest, sure, there are some who search but cannot find work. But what that usually means is they can't find work that matches their specialism. Maybe they could go stack shelves for a bit, but if your prior work was as a senior lawyer it makes sense to take the time to find a job that matches your skills.