Religious services are conducted at a mosque. Prayers offered. Religious teaching happens. By definition, it’s a house of worship. I doubt any court in the land would rule that mosques (generically speaking) are not houses of worship.
It is a state sponsored religion that has it’s own laws known as Sharia. They take over neighborhoods and towns and institute Sharia Law. That is not Constitutional. The First Amendment precludes islam from being a protected “religion”. Their mosques are “community centers” that run under their laws. America and Americans allow it at their own peril.