3 things nobles need to rely upon for their power:
Land
Wealth
Support
They were needed by the monarch to rally support for army as there was no standing army. Played a vital role in the administration of the kingdom. Often governed local regions, enforcing the king's laws and collecting taxes. By delegating authority to the nobility, monarchs could effectively manage vast territories without needing to oversee every detail personally. Forming alliances with powerful noble families was essential for a monarch's political stability.
They also controlled significant economic resources, including land and wealth. By maintaining good relations with the nobility, monarchs could ensure a steady flow of income through taxes and rents, which were vital for funding royal projects and military campaigns.
As much as he would've liked to, Henry didn't attempt to rule without the help of nobility as such would be considered 'wildlyeccentric' - Landers (1980). Elton (1955) & Pollard (2001) argue the War of Roses weakened the Crown but strengthen the nobles.