I have multiple phones- one for Waze, one for WhatsApp, another one for calls. The extra phones cost me $100 each at the time I bought them new - not flagship, but definitely workable. This does not require any real wealth - most western HN reader can afford an amortized $100/year for privacy (half that or less if you buy 2nd hand). I also have multiple emails.
Where I pay dearly, and it’s a cost even billionaires can’t avoid, is convenience. carrying 5 phones around, or remote controlling one from the others, is far from convenient.
Consultant can only take you so far. If you have an aid carrying the 5 phones so they are always available to you, then you have no privacy in a different way.
I have worked with some extremely high wealth individuals, and none of them practices any better OPSec than your average person; some of them inquired but balked at the non-monetary cost (e.g. seeing me with multiple phones, often off until use so they are harder to correlate, etc). These are people who would easily buy 10 iPhone12 max per year if it gave them convenient privacy. But it doesn’t.