The lifeblood of WGT is advertising not equipment or ball sales. Various methods of getting "free" credits have dried up or disappeared over the years that I have played. This is especially true with the computer version of the game,
What this tells me is that advertisers have lost faith in the computer version of WGT as a vehicle to present their ads. I am certain that if WGT could convince companies that they could get a return of some kind by running short video ads, we would have the ability to watch them endlessly.
Once advertising no longer pays enough to keep the lights on, the most likely way for WGT to continue as an internet game will be through a subscription model. Think Netflix or Amazon Prime. Like global warming, this is inevitable because business abhors "free".