Except, gambling isn't illegal here - in fact, it's very common. There are lots of casinos within a few mins walk in any city in Spain. All the prediction markets need to do is comply with existing laws.
Yup, totally nuanced comment coming from a completely sane person since "central planning regulatory hell" and "laissez faire economy without laws" are the two only options we have here, good job carrying the conversation forward with curious and interesting comments.
Sports betting places on the other hand have multiplied like fungi in the last two decades, unfortunately.
You're probably talking about the big Vegas style entire-hotel casino that aren't so popular in Europe anyway outside a niche crowd. The average lower class Spanish person frequents these "sports bars" heavily