"anybody who wants it"

The extent of "anybody" is the detail that contains the devil.

Anybody who? Citizen? Asylum seeker? A person who obtained asylum or other forms of protection? A 'tolerated' person who was not deported? (Duldung in Germany.)

Europe is already politically ablaze, and one of the factors of this blaze is "too many foreigners from the Third World as recipients of welfare". If you introduce any basic income scheme that doesn't totally exclude non-citizens, you can expect the people smuggling gangs of Libya and Turkey to advertise it tomorrow as a next pull factor for their business.