Fixed working hours on flexijob is wrong?

What I find odd about many flexijob listings is that they actually come with fixed working hours, like: “you can work on these days, between these hours.”
But isn’t that basically just a regular job?

I don’t think I’ve ever seen a flexijob where they’re actually flexible and allow workers to submit their available hours (for example 2-3 weeks in advance) or use some kind of availability system.

To me, the whole point of a flexijob is that employees can step in when the employer genuinely needs extra help. But now it often feels like they’re using flexijobs to find workers who can show up on a regular basis, almost like a disguised part‑time contract.

Am I the only one who finds this strange?