<referenceBlock name="checkout.root">
        <arguments>
            <argument name="jsLayout" xsi:type="array">
                <item name="components" xsi:type="array">
                    <item name="checkout" xsi:type="array">
                        <item name="children" xsi:type="array">
                            <item name="steps" xsi:type="array">
                                <item name="children" xsi:type="array">
                                    <item name="shipping-step" xsi:type="array">
                                        <item name="children" xsi:type="array">
                                            <item name="shippingAddress" xsi:type="array">
                                                <item name="children" xsi:type="array">
                                                    <item name="telephone" xsi:type="array">
                                                        <!--Remove item-->

                                                        <item name="tooltip" xsi:type="array">
                                                               <item name="componentDisabled" xsi:type="boolean">true</item>
                                                        </item>


                                                    </item>
                                                </item>
                                            </item>
                                        </item>
                                    </item>
                                </item>
                            </item>
                        </item>
                    </item>
                </item>
            </argument>
        </arguments>
    </referenceBlock>

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="MagentoCheckoutBlockCheckoutLayoutProcessor">
        <plugin name="custom-checkout-process" type="VendorCheckoutPluginLayoutProcessorPlugin" />
    </type>
</config>

<?php

namespace VendorCheckoutPlugin;

use MagentoCheckoutBlockCheckoutLayoutProcessor;

class LayoutProcessorPlugin
{
    /**
     * @param LayoutProcessor $subject
     * @param $jsLayout
     * @return mixed
     */
    public function afterProcess(
        LayoutProcessor $subject,
        $jsLayout
    ) {
        //Remove telephone tooltip
        unset($jsLayout['components']['checkout']['children']['steps']['children']['shipping-step']
            ['children']['shippingAddress']['children']['shipping-address-fieldset']['children']['telephone']['config']['tooltip']);

        return $jsLayout;
    }
}