Italy is not a marginal country. It's the world's 8th largest economy, way larger than such EU heavyweights as Belgium, the Netherlands and Ireland.
> If you grew up in Croatia speaking Croat and possibly English, do you really think the Greek labor market is open to you? Could you in all practicality relocate to Belgium and start a business?
If you grew up in Croatia, you for sure speak English and possibly German or Italian as well.
It would not be as easy to relocate your business as, perhaps from one US state to another, but that's mostly because of local law differences in how a business must operate.
I know people who basically just got up and moved (to the Netherlands, Sweden, Ireland and Germany) and they had no problem whatsoever.