I'm afraid the political problem you describe is much deeper and more entrenched.
The class of aggregated economic interests that brought the western world the "centrist ditherers", as you describe them, are increasingly backing right wing politicians to divide and confuse discontent majorities, now that the social contract is in obvious and advancing decay around us, due to decades of aggressive privatisation of public goods like utilities, education, healthcare as well as related but also wider economic slowdown.
Ironically it was precisely this kind of "centrist ditherer" that spent the last half century destroying these public goods and therefore inflaming the social discontent, which capital must now fuel right wingers to quell.
The guy in the thumbnail (Fernando Haddad, Brazil) has been very effectively taxing everyone except the rich and super rich. The super rich got annoyed that people were buying things from China instead of their resale so he decided to intervene by forcing an import tax of 60% + state tax (between 10% and 20%) over every imported product. Of course, the rich importing these same products to resell on a hefty price increase pay 0 taxes because "they're protecting the national industry".
Taxing individuals by itself cannot solve shortcomings in the tax system. The super rich have corporations and shell companies in tax heavens to avoid taxes.