Anecdotal: The Dutch government offers students free public transit. This allowed me and millions of others to be able to attend a much better (college, uni level) education than I would otherwise be able to have. Or it would involve a 25 kilometer bike ride every day.

Another anecdotal one: Many companies offer travel / commute expense cover. If my commute wasn't covered by my employer, I'd be spending €250 a month out of pocket just to get to work (in addition to the time spent). It would make me reconsider working for that employer in favor of something more local.

I like these kinds of solutions way better than just removing all fare gates, because then you won't have a huge influx of people who will abuse the service and drive away anyone with the means to avoid public transit.

Abstract from your link suggests that the study was pretty inconclusive.

> Findings suggest certain flaws limit the program’s potential success since the program design is misaligned with its primary stated goals, and several program goals relating to external effects of fare reform cannot be evaluated. Although it would be valuable for transport managers in other cities to learn about this experience, the Tallinn fare-free public transport program provides scant transferable evidence about how such a program can operate outside of a politicized context,