what happens if you fail the probationary period every time you get a job?

Every time you get a job? It's likely you are making many mistakes and not doing the job well. Try to get some feedback as to why you failed and what you could / should have done to be kept.

with my current job right now as an estate assistant on the kickstart scheme (not sure if you heard of that, a governments new initiative that are 6 month work placements for those claiming universal credit and at risk of long term unemployment), they decided that they will not extend my current contract and my employment will not continue, but I don’t understand, I only ever made 2 mistakes that wasn’t my fault or it could be because I ask my employer too many questions or insufficient funding (because the kickstart scheme pays them for 6 months to pay us at minimum wage).

Sadly a lot of employers take cynical advantage of these schemes to get 6 months etc cheap/subsidised labour, then mysteriously lose interest when the subsidy dries up.

Its been the same for the Youth Training Scheme, Skillseekers and the others that came before...

so basically it’s a scam, like my contract said if I am good enough, employment continues, if not good enough they either extend your probationary period or terminate your employment at any time.

If these government schemes are scams, why is the job centre forcing every universal credit claimant to get a job on the Kickstart scheme?
I heard some apprenticeships are scams too, if the government creates these schemes, why are some of them scams?

It CAN be a scam, yes, people on probation periods have v little employment rights so some employers have an interest in keeping you that way

As for the job centre, they'd rather see you out working and gaining experience either way (and off their personal caseload) whether you get paid/a contract or not. Many of these employment schemes are frankly aimed to help the employers with cheap labour more than you,

There's simply a lot of people who think the unemployed should be forced to do something at all time or be kicked off benefits, and we keep voting for a historically mean and corrupt Tory government who put their business pals first. So it'll keep happening.

is this only for entry-level jobs where employers use you for manual cheap labour or is this the same with graduate jobs?

going a bit off topic but if you don’t have a degree, are you stuck at low paid manual working class jobs/you won’t be able to do anything academic and using your brain and getting the top jobs?