Does Islam Only Have Five Pillars?

Hudhayfah ibn al-Yaman said: ‘Islam is divided into eight parts. The prayer is one part, zakat is one part, fasting is one part, hajj is one part, ‘umrah is one part, jihad is one part, commanding what is known to be right is one part, and forbidding what is recognised as wrong is one part. Disappointed is he who has no part of Islam.’

Imam Ghazali’s Views on the Importance of the Caliphate/Imamate

"Let it be noted of the first generation, as to how the Companions (رضي الله عنهم) hastened after the death of the Messenger of Allah ﷺ to appoint the Imam and contract the pledge of allegiance, and how they believed that it was a conclusive obligation (farḍ), a right and mandated (wājib) with immediacy and urgency, as well as how they left the preparation of the Messenger of Allah ﷺ (for burial) through being busy with it (appointing the Imam)."