‘Only’ is a bit simplistic: there were periods of oppression there too (like the Massacre or Granada in 1066, and there was always a level of discrimination against all non-Muslims (who were the majority) we’d find unacceptable by today’s standards.

It was far more tolerant of Jews than most of Europe, but the Middle Ages saw other periods and areas of relative religious tolerance, like Poland under Casimir the Great, which is why many Jews moved there (he also married a pagan Lithuanian princess, and was relatively enlightened for his time).

Similarly, Jews in the Byzantine Empire were mistreated by earlier emperors but from around 700 onwards they had a golden age of their own, until the Fourth Crusade brought more intolerant Frankish rule.

Most of the major countries of Christian Western Europe expelled the Jews at some point, and there were intermittent massacres, blood libel and discrimination across it. But Medieval Europe as a whole was a very large, diverse region over the course of a millennium.