The government could incentivize this by a tax formula. Highest paid employee divided by lowest paid employee sets the payroll tax rate for the whole business.
They could, but a lot of idiot children decided not to support the party that would have done that because unnamed randos on the interwebs told them not to. So that’s not going to happen. Again.
Not sure exactly which country you’re referring to, but in the USA the Democratic Party absolutely would not do that, which is precisely why they lost. If they had accepted the popularity of Bernie Sanders in 2016, maybe. But the party decided not to go that direction.
Their next presidential nominee is probably Gavin Newsom, who grew up in private school and best friends with Oil money billionaires - the Getty family.