As I remember President Kennedy was riding in a motorcade with a big entourage but in an roofless car, making him a perfect target, when he was shot by a sniper. Since then presidential security has been beefed up.
There is a story that in the early 20th century the king of Greece took a walk alone in Athens. When he came back to the palace there was an anti monarchy protest in front, so he joined the protestors until they dispersed and then he went back inside.
Warren Buffett has never been the richest person in the world, and never been higher than # 3. Because he gave away so many billions of dollars to charities, today he "only" has a net worth of a "mere" 117 bilion dollars. But he is still very, very rich. And I have read that he lives in rather ordinary house in a rather ordinary neighborhood instead of a great mansion on a great estate. It doesn't sound like he always has a bunch of attendants when he goes out.
King Olav V of Norway died in 1991. It is said he drove his own cars and paid his fares when he took public transportation.
On Friday, 28 February 1986, at 23:21 CET (22:21 UTC), Olof Palme, Prime Minister of Sweden, was fatally wounded by a single gunshot while walking home from a cinema with his wife Lisbeth Palme on the central Stockholm street Sveavägen. Lisbeth Palme was slightly wounded by a second shot. The couple did not have bodyguards with them.
On 18 February 1853, Franz Joseph survived an assassination attempt by Hungarian nationalist János Libényi. The emperor was taking a stroll with one of his officers, Count Maximilian Karl Lamoral O'Donnell, on a city bastion, when Libényi approached him. He immediately struck the emperor from behind with a knife straight at the neck. Franz Joseph almost always wore a uniform, which had a high collar that almost completely enclosed the neck. The collars of uniforms at that time were made from very sturdy material, precisely to counter this kind of attack. Even though the Emperor was wounded and bleeding, the collar saved his life. Count O'Donnell struck Libényi down with his sabre.
O'Donnell, hitherto only a Count by virtue of his Irish nobility (as a descendant of the Irish noble dynasty O'Donnell of Tyrconnell), was made a Count of the Habsburg monarchy (Reichsgraf). Another witness who happened to be nearby, the butcher Joseph Ettenreich, swiftly overpowered Libényi. For his deed he was later elevated to the nobility by the Emperor and became Joseph von Ettenreich. Libényi was subsequently put on trial and condemned to death for attempted regicide. He was executed on the Simmeringer Heide.
So the Austrian emperor took a walk without bodyguards.
Franz Jospeh was the powerful ruler of his empire, and so was responsible for government policies that many people might resent for various reasons. But the monarch of the UK was a ceremonial head of state by then, so nobody would resent Queen Victoria or want to kill her, right?
On March 2, 1882, Roderick MacLean attempted to assassinate Queen Victoria at the train station at Windsor. She was starting to ride to Windsor Castle in her carriage, cheered by schoolboys from Eton, when Maclean shot at her. The schoolboys wacked Maclean with their umbrellas until he was subdued. That sounds like Victoria didn't have professsional bodyguards at the scene.
Well why should anyone think that the beloved queen needed bodyguards, since nobody ever tried to assassinate her before? Actually Maclean was the eighth person to try to assassinate the queen, so maybe they should have thought of giving her a bodyguard detail by then.
The present royal family of the UK does have professional bodyguards and security precautions. But sometimes those in charge of security aren't vigilent enough.
On 9 July 1982, queeen Elizabeth II woke up to find an intruder, Michael Fagan, in her bedroom in Buckingham Palace. I have read that she is always polite and gracious, but I imagine she must have been strngly tempted to get sarcastic the next time she discussed palace security.
Anyway, these few examples show that sometimes rich, famous, and/or powerful people sometimes don't have a bunch of bodyguards or assisants around to protect them.