Bulgaria is not a country where it is so safe and comfortable. Many European countries are raising taxes. In Poland, the tax is already 19%, and in a year or a year and a half in European countries there will be almost the same tax. If you are satisfied with such a tax, then this is your choice.
I've lived in most of Bulgaria's main cities, and I can confirm that I feel much safer here than in any Western European country I've ever known (I was born in France, and I've lived in the UK, Germany and Spain). I think anyone who has grown up in Western Europe and then lived in Eastern Europe would agree that insecurity is a very Western thing in Europe.
10% of flat taxes is good for me, I can't think of a better alternative in my personal situation. Perhaps Malta or Gibraltar would be more advantageous, but what I would gain in taxes, I would lose because of the higher cost of living.