Not true for Monaco. They will go to such lengths as watching the CCTV footage that had been recorded of you in order to see if you are actually present in the country.
As I said if you are French citizen all this tax haven sugar isn't valid for you, Monaco banks will report you to French authorities, but for rest of the world it works (unless something dramatically changed in last year or two).
Not true for Switzerland: You have to be 6 months per year here to officially / taxwise "live here". Otherwise, you lose your permit. The same is true for Singapore, I believe.
If you come as an outsider to Suisse, private banks/tax companies will either refer you to their branch in place where this applies to you, or if your net worth is high enough (can't remember exact threshold but it should be in 5 mil CHF ballpark and above), you can literally buy citizenship and you're covered (ideally in Zug/Luzern as one can witness in local property market there but it always depends on the case).
Hiding usually means just avoiding paying most of the income taxes (ie 5% instead of 40% or even much more in places like Scandinavia). In most countries, tax brackets for really high incomes are just ridiculously high, so everybody seeks to pay less taxes while staying legal. Taxes are a sinkhole from rich payer's perspective - you get back very little and you pay a lot.
It's like expecting common Joe not claiming some tax breaks he is entitled to. Why on earth would he not do it?
What exactly is untrue in my posts? Happy to learn more. My posts are quite generic for the topic, since we're on public internet forum but they come from my knowledge on this topic (which might be obviously invalid).
Why do you think normal flat in Monaco costs up to 20+ million eur? It is a nice place, but not THAT nice (In MCO case you need only postbox which can be rented cheaply as many professional athletes do... unless you are French citizen, then you are screwed but can go elsewhere)