Say if someone owns 10 Bitcoins which is not declared and government doesn't know about it (earned/mined etc but did not buy) and now that someone want to avoid paying tax on cashing it out. Can he simply move to countries where there is 0 tax like (UAE) specifically dubai and setup a company there and cash out crypto over years in dubai bank account and later decide to move to his home country with all that money. Since dubai has 0 personal tax and his home country can't charge tax on it because of non-resident of home country. Is this possible?
I have friends who did this. There are no taxes on cryptocurrencies in Dubai, but there are many other nuances.
To open a company and get a license, you will have to spend 10-30 thousand dollars. This procedure takes 3-6 months or more. Renting an apartment in Dubai is 5-10 thousand dollars per month. You can live in a hostel with workers from India and other countries

it's cheaper there. Dubai is very expensive.
The cost of flights, accommodation, company registration, tax services, legal services will take you a very large part of your savings.