Joomla 4 has been out for a while. The number of compatible extensions and templates is still limited. If you are looking for a free template for Joomla 4, this article will help you.
Next are the providers of a large number of free themes. However, I do not appreciate it because some features are cut and only available on the paid version. The templates are distributed across all categories, you can try it out before you decide to upgrade.