Three decades ago, Jonathan Gray might have been an unlikely candidate to become Blackstone’s president and expected successor to its chief executive, Stephen A. Schwarzman.Very little of Mr. Gray’s career at the private equity firm has involved leveraged buyouts — the aggressive deals, often involving large amounts of borrowed money and steep cost-cutting, that gave private equity its rapacious reputation. Instead, he has spent most of his time in Blackstone’s comparatively staid real estate business, helping the firm become one of the biggest property owners in the world.Mr. Gray’s elevation to president in 2018 reflected Blackstone’s growth into a behemoth with a hand in just about everything: mortgage lending, infrastructure, television and film studios, stakes in entertainment companies, pharmaceuticals, and even the dating app Bumble.Blackstone is in the vanguard of an industry leaving its roots far behind. Since the 2008 f …
