If voters are allowed to lobby, then a voter who owns, is employed by, or is a customer of, or chooses to represent my company can lobby on my behalf... and that's actually what's happening anyway!
Obviously a company as an abstract entity does not lobby. An individual human being lobbies. A voter.
That's the problem, isn't it. Sociopathic wealth hoarders should not control the population, and any scheme in which they do it anyway is problematic. That includes delegation.
Obviously a company as an abstract entity does not lobby. An individual human being lobbies. A voter.