several things need to be taken care of for this purpose and requires a custom module created
1, remove reset password link from customer account dashboard page
to remove the link we need to create a customer_account_index.xml file in your custom module to rewrite template file Magento_Customer::account/dashboard/info.phtml
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="2columns-left" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceContainer name="customer_account_dashboard_info">
<action method="setTemplate">
<argument name="template" xsi:type="string">[Name_Space]_[Your_Module]::account/dashboard/info.phtml</argument>
</action>
</referenceContainer>
</body>
</page>
then you can copy the magento template vendor/magento/module-customer/view/frontend/templates/account/dashboard/info.phtml to your own module and remove the reset password link in it.
A dirty hack if you don't want to rewrite template is to add a custom css rule to hide the link
.action.change-password {display:none;}
2, remove password reset checkbox from customer account editing page
similarly like in step1, we need to rewrite template vendor/magento/module-customer/view/frontend/templates/form/edit.phtml from customer_account_edit.xml layout to remove the reset password checkbox
3, remove the forgot password link from login page
again, rewrite template vendor/magento/module-customer/view/frontend/templates/form/login.phtml from customer_account_login.xml layout to remove the forgot password link
4, if you are worried about people bypassing frontend and sending password request directly to server, create a aroundChangePassword plugin for Magento\Customer\Api\AccountManagementInterface to not reset password and return a friendly message back to customer.
