Large (capable) law firms would not want to associate themselves with the underdog in this case. Either because they want to avoid conflict of interest, or confidentiality matters as they likely already have an ongoing relationship with the company initiating the lawsuit. Or simply that the bigger guy paid them to "counsel" and now they have to recuse themselves due to this "relationship".

The smaller guy also likely isn't rich enough to pay for a major law firm either. The game is stacked completely against the individuals going solo against the megacorps. There is no way to win.