Why are 3rd part platform like job prep test allowed for online assessment?

So banking and consulting (and more) use only assessment including numerical,sjt and more.
These assessment for specific firms like Morgan Stanley or multiple banks can be bought for prices like +100. If you want to apply to multiple different industries which have different packages then you need go pay another £+100 etc ...
So fundamentally these firms who claim to be for equal opportunities use the same questions and providers so 3rd party platforms can copy it and provide a service which only the rich can afford. Fundamentally this isn't for equality.
So either want you to pay alot or create multiple accounts and cheat that way. They creat an incentive and those who don't loose out.
I mean those who study maths or physics or economics fail numerical assessment not because they are hard because they have time limits or other people just have those unfair edge. And wtf is abstract reasoning 💀. It has no indication on anything .
So my question is why do the firms allow this idk change their OA yearly.

You're honestly asking why investment banks don't fully embrace equality?