While fed and some state tax incentives for both have existed for more than 40 years in the US, I think it may be too late for these alone to do much good in anything other than a continued growth/full employment scenario. 

In any other scenario, e.g. jobless growth and/or mostly low-wage job growth, not to mention various types of stagnation, decline, and collapse scenarios, profit sharing and employee stock ownership could not only be useless, but could also result in employees losing income (especially in the case of stock ownership).

However, had either become the norm, rather than the exception, in corporate American at least 30+ years ago, they may have reduced the increase in income inequality resulting from the combo of automation and outsourcing (job exportation to cheaper labor markets) over the same time period. 

Such incentives MIGHT still be useful before automation runs its potential full course, but probably less so for the growing number of "gig" economy workers