With more than 3 million installs WPForms is arguably one of the most popular form plugins ever. It includes a Gutenberg block for easy form selection.
Extract from WordPress.org
WPForms’ contact forms are also highly optimized for web and server performance because we understand the importance of speed when it comes to SEO, marketing, and conversion. We can honestly say that WPForms is one of the fastest WordPress contact form builder plugins in the world.https://wordpress.org/plugins/wpforms-lite/