In my view not speaking English is the biggest disadvantage of many European countries:

People from other countries will have a substantially easier way of integrating into society in the UK, Canada etc. because there they won’t have to choose between having to learn a new language or have difficulties finding jobs and navigating everyday life (like joining a sports club etc. ). Here in Germany the trend goes definitely towards more English speaking companies, projects and hobby groups but obviously English speaking countries will always have a substantial lead in that. Honestly if I thought about emigrating, my first thoughts would also be about some English speaking countries. So you will get by in Germany with English but it’s highly desirable to learn German in the long run (which isn’t only negative as learning other languages is good for ones brain, widens the horizon and is kinda cool).

That being said (take it with a grain of salt as I might be biased) the European Union and Germany still are good options because of

• the amazing travel opportunities (Italian beaches, hiking in the Alps, millennia old cities like Rome, Paris and Prague etc.) just around the corner
• attractive citizenship path (in Germany maximum five years)
• relative democratic stability (in Germany: the AfD “only” has 20% voters with the remaining 80% strongly against cooperation and in big cities where most foreigners live it’s substantially lower - moving into another European country is in the worst case also with hurdles)
• solid economy (in the past two years stagnating but for example the new infrastructure bill will change that probably)
• with for example the Max-Planck-Gesellschaft and the Fraunhofer-Gesellschaft Germany has some prestigious and productive research institutions
• …

On a more meta level non-English speaking countries might also have a disadvantage due to not even being considered in the first place because they are less prominent in the English speaking media.

Edit: Btw. the wages and working conditions in Germany in public research aren’t very high but I assume that applies worldwide to research, which isn’t funded by a company.

Edit2: The first points probably relate less to researchers than to other professionals as for scientific researchers it’s more common to work in another country and to move on after some years (at least that’s my perception as a non-expert).

Edit3: As far as I know the salary for researchers and professors can be quite higher than in for example Germany. However here you’re supporting an academic system that excludes poor people less.