This is wild & so, so wrong.
It is completely & utterly different in Scotland. PSAs (pupil support assistants) - the equivalent of TAs I imagine- are very, very far away from teachers. They do a phenomenal job, and with constant cuts we couldn't survive without them, but they support, they don't ever teach.
Some responsibilities they may have:
Organising equipment/ photocopying resources/ prompting /reading for a pupil/ scribing for a pupil/ reiterating instructions/ explaining steps again/ looking after disability needs (lift access/ medical needs)..
Absolutely never teaching a class, or being alone with a pupil or group of pupils. It would be within a classroom with a teacher. There is no planning/ marking/ admin.
I'm in secondary, and I imagine the primary role is somewhat different, but they would never teach a class, ever.
I've been teaching 30 years, & have presented 1000s of pupils for our national exams (equivalent of GCSE & A Level), so whilst PSAs/ TAs do an amazing job for very little pay, their job in no way resembles mine, so they are indeed not teachers (and wouldn't want to be, I imagine).
Edited to add: here we need a degree plus the PGCE to teach your subject. There's no teaching another subject until a certain age (like they do in other parts of the UK). Then there's also a probationer year, which is very robust, & you must pass, and finally another 2 years of 'probation' within a school environment. Never, ever just learning on the job.