The Dutch allow companies to negotiate individual rates which are kept secret. No, this is not competition, it is corruption.

Economic agency is not corruption. It's no different from negotiating tax breaks with local governments here in the United States.

You're right, it's no different: both are corruption.

Can you prove how it's corruption?

You're right, it's proven beyond doubt that it's corruption

I mean, you’re free to blindly dismiss obvious corruption - but it’s quite obvious that these loopholes were designed, and often illegal.

Eg, https://en.m.wikipedia.org/wiki/Ireland_v_Commission

The article you posted states that Apple won their appeal against the finding of illegality in the ECJ.

Taxation is not an EU competence so in general it is not within the power of the EU to declare a member state's tax policy to be illegal. Vestager has been trying to use state aid as a vehicle to circumvent that restriction but the ECJ rebuffed her attempt to do that in Ireland. A big part of the problem is that the state aid findings rely on the assertion that tax authorities applied special rules to one particular company, which is typically not the case.