Commento is a platform that you can embed in your website to allow your readers to add comments. It's reasonably fast lightweight. Supports markdown, import from Disqus, voting, automated spam detection, moderation tools, sticky comments, thread locking, OAuth login, single sign-on, and email notifications.
Most other products in this space do not respect your privacy; showing ads is their primary business model and that nearly always comes at the users' cost. Commento has no ads; you're the customer, not the product. While Commento is free software, in order to keep the service sustainable, the hosted cloud version is not offered free of cost. Commento is also orders of magnitude lighter than alternatives.
For starters, your readers value their privacy. Not caring about them is disrespectful and you will end up alienating your audience; they won't come back. Disqus still isn't GDPR-compliant (according to their privacy policy). Disqus adds megabytes to your page size; what happens when a random third-party script that is injected into your website turns malicious?
Read the documentation to get started.
If this is your first contribution to Commento, please go through the contribution guidelines before you begin. If you have any questions, join #commento on Freenode.