Which is almost always, as almost all EU countries have better conditions than Bulgaria. So in general you can assume a position with significantly worse social status than you had in Bulgaria, but if that position is in Germany, that is a net social benefit for you. So that's what you often do.

Bulgarian butchers in Germany, obviously, do not have native German to communicate with customers, and their butcher skills may be tailored to a different meat culture, so they are hired because Germany have more butcher positions than Germans want to occupy, and that German butchers will usually take the ones which pay more. Same for Bulgarian software developer in France: They have decent coding skills and English, but their French is no good, so they will be kept in more back-office roles, whereas French developers from France will be more customer-facing and paid somewhat more for this skill. That's pretty basic migration economy 101.

In Comecon, Bulgaria was one of more developed regions, which then got to host more prestigious industries.