If that was good business then presumably the brand could have done it at some point during their long slow decline?

Arguably, they're a better choice for customers than a shutdown.

I mean, they're at least keeping the service alive for as long as possible.

There’s no choice here, and often the companies are profitable, but if there is any stickiness to the product the customer gets the privilege of having a company they built trust with turn around and betray them with massively increased fees.

I'd argue it's worse for consumers, by keeping them alive it staves off competition, and leeches cash by increasing subscription prices or locking once free feature behind paywalls.