Why would Musk merge SpaceX and Tesla?

Elon Musk has publicly expressed his support for a potential merger between Tesla and SpaceX. According to the reports, Musk believes that combining these two companies is a positive move. Such a strategic consolidation would result in the creation of a singular corporate entity with an estimated total valuation of approximately $3.5 trillion. This move reflects Musk's vision for integrating his primary ventures into one of the most valuable companies in global history.