This is a philosophical difference, in a way - running an asset-light business vs an asset-heavy business. Hotels have mostly moved towards not owning their properties, for example.
Increasingly, many new orders of aircraft are leases. However, they are not usually leased directly from the manufacturer. The airplane is usually owned by a holding company ("trust"), and tranches of the trust are sold to investors - somewhat similar to a mortgage bond.
The benefits of this is that investors from all over the world can invest directly into the airplane, then lease it to the airline. The plane itself is the collateral, and international treaties make it easy for investors to retrieve the plane if the airline isn't making its lease payments. They could then choose to lease the plane to someone else, sell it to someone else, or to scrap it for parts and materials.
What are the benefits for airlines? Typically, if things go south, they don't owe anything beyond giving the aircraft back. Also, given that many US airlines have gone through Chapter 11 recently, I'd assume they wouldn't get great interest rates if they actually want to buy the plane - it's likely cheaper for them to lease through an EETC. For example, American Airlines issued a bunch of EETC's the past few years.
It's a fairly niche subject, so the wiki page isn't too great, but here it is: https://en.wikipedia.org/wiki/Equipment_trust_certificate