Hilton offers a lifetime status. IHG does not.

Lifetime Hilton Diamond requires 1,000 nights or $200,000 in base spend at hotels. Likewise Hyatt Globalist. Both are the top level in their respective program.

Marriott offers lifetime status at its three lowest (of five) levels: Silver (250 nights & 5 years), Gold (400 nights & 7 years), and Platinum (600 nights & 10 years). Only the latter offers any meaningful benefits. Unlike the other two chains, "nights" can be earned through (U.S.) credit cards, so it is by far the easiest lifetime status to earn (for Americans).

In the IHG versus Hilton calculus, lifetime status should only be a consideration if one is likely to stay 1,000 nights (or its base spend equivalent) over the course of one's travelling years.