It's because the money isn't given to the politicians or their campaigns. The money is spent hiring the lobbyists, and their teams to dedicate manpower to finding convincing arguments which can then be presented to the politicians.

Yes lobbying is usually associated with evil corporations, but the fact of the matter is that in order to fix it you would need to remove the power for citizens to speak to their representatives.

Lobbying is, as far as I know, legal in every functional democracy.

I think you are confusing this with campaign contributions, which is a different but related activity.

I'm not aware of lobbies, established for a specific purpose, with offices and personel, and getting donations, in any functional democracy I know of.

Lobbying in the UK sure sounds like lobbying in the US to me.[1] So does Volkswagen's lobbying of the EU parliament.[2] Do you have an example of a functional democracy that doesn't have lobbying like this?

[1] http://www.lobbyingtransparency.org/

[2] https://uk.news.yahoo.com/volkswagen-scandal-puts-eu-lobbyin...