What challenges do expats face in obtaining work permits for teaching in Thailand?

I made a comment on another post about finding it difficult to get a work permit here teaching

My teaching job was in college teaching local and international students, to work with children youth and familes, also to work with people with disabilities, mental health, victims of family and domestic violence, sexual abuse of minors,

Children and youth at risk of abuse.

Its called community services work chc5012,

There doesnt seem to be much call for that here, which is why its difficult,

I have been offered English teaching jobs off the books.

I just wanted to clarify this as not all teachers teach english or work in primary or secondary schools.