They compete for finite dollars, too.

There was a time when regular families had desktop computers at home. The marketing was intense, the machines were expensive, and the sales numbers were real. The PC was the gateway to all of the spoils of the internet and things were booming.

Now families tend to have a collection expensive personal pocket supercomputers, instead. It's hard to justify the cost of a properly-stodgy computer when everything is online and the machines that everyone already has in their pockets are Good Enough to get things done (including entertainment).