Because creating a new product is harder and more expensive than changing an existing one, even if it does destroy it.

Advertising, novel technical infrastructure, new branding, etc... all of this needs to be done for a new brand -- and then who knows if any one will come visit?

Or, you can just make whatever short-term changes to your existing successful product, juice the metric you're looking to juice, and (in theory) cashout before the long term repercussions take affect.

New branding isn't necessarily bad; it can make a new product seem fresh. Technical infrastructure, both hardware and software, can be reused. You don't have destroy one software product to make another.

Take this OkCupid example; they had their website model. They could have just created "OkCupid Nights" as a separate Tinder-like product reusing as much of their tech as possible.

Well, the existing product already has critical mass, a new product - like the various Instagram clones, then the various Tiktok clones, then the various Twitter clones - all have to acquire their own customer base.

That said, other point: Why not just accept you're no longer growing? The company would've stayed solvent for years yet, with a steady group of users coming in and out over time as the brand becomes synonymous with thoughtful dating profiles instead of the rapid fire hot-or-not that is Tinder.

The endless pursuit of growth is incredibly destructive. A consistent profitable business is considered a failure.

Instragram was able to pull their users into Threads pretty easily without making Threads a direct part of Instragram. It is still it's own thing with it's own brand.