They murdered a journalist in cold blood. It's not hard to imagine what they would do to Amalia or the PM. (Mountbatten was killed on holiday, not while not being allowed to leave the house, and I never heard of the Spanish royals having their lives or holidays restricted, either, even with terrorist threats.)
Prinsara, the Spanish royals had their whole life limited by security regulations, but it was not a topic that they ever talked about or complained about publicly... because in a country where many people lived with bodyguards and there are so many possible targets that you can't protect them all (ETA had very broad objectives that included councilors from very small towns, businessmen or university professors), and there were people who died from gunshots in the head or because a car bomb exploded near them (including children), complaining about the restrictions when you have all the security of the State at your service is not ethical.
Juan Carlos was in Mallorca in the sights of a murderer who wanted to shoot him in the head, the family did not stop going to Mallorca on vacation, security was reinforced.
Prince Felipe attended a public university in Madrid for 5 years. Every day he arrived at the university in his own car with his bodyguards, the car and the facilities were checked with dogs that detected explosives, he always went to the same classroom in a more protected area and the group of classmates remained during his years of studies, that group of classmates included some undercover police, only years later his classmates found out that those boys were actually policemen. That was his routine and he lived with it, because he knew that in Spain there were young politicians who did not have bodyguards, and that when they went to university they had to follow self-protection routines.
In 2015, some calls were intercepted from a jihadist group threatening the king and his daughters, in the country that has suffered the biggest attack in Europe, obviously that is a very serious issue... and publicly there was no comment.
Princess Leanor is currently studying in Wales, and is accompanied by a security team. Outside of school she is probably much more restricted in her movements than her peers, including Princess Alexia, and as much as it annoys her she knows it must be.
When a terrorist or mafia group is involved, it is the security forces and intelligence services that have to do their job, and always with discretion. In the face of a threat, discretion and reinforcement of security, and if that includes limiting your movements, it is something that goes with your privileged position.
For me, the only thing that Máxima has achieved with these statements is to give international repercussion to the issue, and the mafia group must be delighted because their threats have worked, because the Queen of the Netherlands herself has said that they are locked up at home, giving the impression that the Dutch police are unable to keep them protected.
I also imagine that in the Netherlands there are many people affected by this mafia, from port workers threatened to work for them, to people who may be involuntarily affected in the middle of a confrontation between them or the thousands of young people who consume the drug with which they traffic... That the Head of State and his wife focus on the problem that their privileged daughter cannot have fun like a normal teenager seems to me to be an error from the point of view of communication. As happened with the Covid restrictions, they comment on things as they affect them personally, and not as problems that affect the entire community, and many people who are not in their privileged position.