edit: mrtksn's comment hits the nail on top of the head.
Your data for Croatian dev salaries is mostly accurate - junior hires will net up to €1k, if they have some exp (interns or good personal projects) that miight go to €1.5k. Actually €1.5k is median dev salary, with seniors fetching €k2 net and team leads maybe up to €2.5k.
Note that this is all net monthly salary. Taxes, social, medical and pension contributions (all witheld by employer) add to roughly again that amount for these salary levels. Here's a recent survey (in Croatian but you'll be able to make sense of the charts and tables) with a lot more details (PDF): https://www.ictbusiness.info/media/infografika/developerske-...
Then there's freelance work, which exploded in recent years, partly due to a miscalculated tax break: if you're freelancer and register as a sole proprietor, you pay miniscule tax for up to €40k per year, handily beating most local companies' hiring budgets.
This lead to massive uproar by said companies, and there's now quite heated debate around the minutia of it. There are primarily two reasons for the complaints: first is that remote companies (which often hire these freelancers on full-time basis) basically get 50% discount, and the second is that local companies started laying off people and "conntracting" them as "freelancers", which is illegal but the guidelines on how exactly that's determined are extremely vague.
And that's just one country :)
That corresponds to a gross pay of ~ US$96k, which gets a decent middle class life in many parts of the U.S. (you can live pretty well on that if you choose a non-coastal city.) You can even live decently in America's 3rd largest city (Chicago) on that.
I'll bet that goes a much longer way in Sofia.
FYI as an experienced professional I have just been pitched a couple of civil service jobs in London grade 8 to Grade 7 at around 75k - and that would give me about 6.5 k
That's the eqvielent of a full Colonel / GS15 if its the higher grade.
And I bet a FANG in London pays way more than that as do train drivers
Mortgages in a similar country start from 6%.
Anyway, Central bank has interest at negatives, people are buying houses in EU with very little interest.