Forcibly remove the tax line item and calculation from the cart. (suggest just using the GEO setting in WooCommerce)

functions.php

<?php 
// Remove the Tax Line item from the cart.
function wc_remove_cart_tax_totals( $tax_totals, $instance ) {

	if( is_cart() ) {
		$tax_totals = array();
	}

	return $tax_totals;
}
add_filter( 'woocommerce_cart_tax_totals', 'wc_remove_cart_tax_totals', 10, 2 );

// Show the cart total excluding tax.
function wc_exclude_tax_cart_total( $total, $instance ) {

	// If it is the cart subtract the tax
	if( is_cart() ) {

		$total = round( WC()->cart->cart_contents_total + WC()->cart->shipping_total + WC()->cart->fee_total, WC()->cart->dp );

	}

	return $total;
}
add_filter( 'woocommerce_calculated_total', 'wc_exclude_tax_cart_total', 10, 2 );
add_filter( 'woocommerce_subscriptions_calculated_total', 'wc_exclude_tax_cart_total', 10, 2 );