Yes ? If everyone suddenly started using English instead of Croatian it would be a net positive in my book. I'd probably get a lot better at casual English which is something I notice talking with non-Croatian speakers outside of work.

I'm not saying we should force adoption of English ! Tech and globalisation are pushing in that direction in the "west". People I see pushing back the most are "intellectual elites" invested in the language, presenting their value judgements as objective arguments.

But everyone wouldn't suddenly start using English, that's not feasible. Is everyone in your family fluent in English (my family is not)? In every country, there are people who couldn't adapt and disproportionally so in vulnerable groups. Suddenly, you would be in a country where you don't know the language. Everyone would be immigrants in their own country.

Protection of national languages is as much on the agenda of politicians, including right-wing populists. In your view, are the songs, stories, books and plays in Croatian the property of the elites and not of every Croatian?

You say we wouldn't force it, but if we left it to Hollywood etc. they would force it. Leaving issues for the markets to decide freely brushes aside all the negative externalities.