It’s important to remember that most billionaires/ millionaires are not celebrities, money doesn’t always come with fame attached. Ask yourself – how many billionaires do you know by face? If your answer is zero, then think of the 1846 billionaires that you don’t know of and they could be standing next in line to you at the customs at the airport or in a hotel reception or even at a petrol stations. (There are roughly 1846 billionaires in the world according to Forbes. Excluding dictators, mafia, monarchs and like.)
The rich go out just like you and me, they even do food shopping just like we do. I’m sure they don’t want to be surrounded by bodyguards for no apparent reason. It’s called freedom and everybody likes it, bodyguards are only required in high-risk situations.
In some countries there is a certain degree of animosity towards people with money, even if he or she has acquired their wealth legitimately. These people are often considered crooks especially in third world countries. It’s nearly impossible to meet a millionaire in developing countries. Furthermore medium to high profile politicians have bodyguards and armoured cars.
Usually they don’t have anything that anyone would be likely to set upon them for. They’re not celebrities, so no-one is going to hassle them for autographs or attention. Most millionaires don’t look rich in a way that would be recognisable in our celebrity culture. At most, some look upper middle class. If you saw them shopping in Tesco you would think they’re not even upper middle class.
So just to summarise: It all depends on the principles public profile and whether their life is under threat. For example if a millionaire made his money by creating a successful haulage company, it’s very unlikely that he would need the same level of security detail as a Hollywood film actor, due to their prominence within the general populous.