If it were true that this was all caused by black cab drivers pulling strings, Uber would have been thrown out of London years and years ago.

Multiple mayors - including the current PM who was once Mayor of London - have explained that there needs to be an open culture.

There are other private hire vehicle operator firms in London. Addison Lee is huge, and there are many, many "minicab" firms. They all comply with TfL's licensing and vetting procedures. Uber does not.

This isn't "black cabs vs Uber", this is "black cabs, Addison Lee, all the minicab firms, TfL and the Mayor of London demanding basic vetting procedures that everybody else does without question or issue".

Black cabs are in their own category due to The Knowledge and the general vetting process, but if what you say is true, why don't we see Addison Lee, minicabs, Kapten, Bolt and Ola getting the same level of scrutiny? Do we have any reason to believe that any of those have implemented policies and procedures that make them more fit and proper?

That is certainly possible -- although I tend to give them the benefit of the doubt.

However, if that were the case, why not just say no license? Why give an opportunity to Uber to show an improvement in their numbers? And why do it twice?

It's not all or nothing, and no one is suggesting that the taxi commission is 100% corrupt and in thrall to Big Taxi. The way they're approaching Uber is likely a compromise between kowtowing to business special interests and serving their constituents (as pretty much all policy in every country is).

it really doesn't. The worst they'll do it block off a bridge.

Plus, there are two taxi systems, the Black cab, and the minicab. There are way more minicabs than black cabs, and they are a much bigger competitor to uber than black cabs.