Michael Saylor pulled the same move six months ago and explains it really well. Highly recommend watching any of his interviews. The one with Preston Pysh is particularly enlightening.
Essentially bitcoin is a really good store of value with superior monetary properties to all other assets. If you want to store wealth for a hundred years there's nothing better. Even gold has 2% devaluation per year and has custodial risk, whereas bitcoin has no devaluation (21M supply cap), is easy to self-custody, and is very secure (high energy use/decentralized).