I can't vouch for this specific organization, but i'm very familiar with similar organizations. This kind of organization runs on volunteers, many of whom have experienced poverty firsthand, and virtually all have experienced poverty secondhand. This kind of volunteer work is typically people actually caring, not people 'virtue-signaling'. This kind of work is done in intimate collaboration with municipal social services, which are typically well-respected in the Netherlands.
There is no doubt in my mind that everyone involved is intending and capable of affecting a change for good.
> I wonder how effective life coaching is to people in poverty.
I've personally volunteered as a coach in poverty situations. It works. The coach doesn't need to do much, just listen to the problems people cope with, and occasionally point them towards a resource that'll help them is enough. Just being able to vent to someone who knows how it feels to deal with poverty might be enough. If it's not, helping people navigate social services and programmes typically ends up lifting them from poverty.
It helps that in the Netherlands, poverty is typically unnecessary. There is (almost) guaranteed livable income for everyone independent of employment, due to our strong social security system.