To clarify, it's $99/year, not a one-time fee. With developer mode sideloaded apps expire after a year; without it only 7 days.

Why isn't it free, or a nominal one-time $20 fee like the Microsoft Xbox developer program? Very good question.

Can't Apple close a developer account if it's never used to submit an app to the app store?

I've had one for ~8 years now I think and never have? I just use it to get early access to betas and such. Which is a valid use case, if you have internal software you want to test or something.

I've had my dev account for years before I submitted my first app to the store, so I don't think so.

I did some checking and it looks like Google is the one that's disabling inactive accounts.

Google must be pretty lax then. I bought a Google Play license in 2013, and proceeded to upload a handful of shitty apps that have all been auto-removed at this point. My dev account still works just fine, so ymmv.

Microsoft recently closed a ton of “inactive” Xbox dev accounts, maybe that’s what they thinking about.

(Accounts that were inactive from publishing apps/games to the store. The accounts may have well been “active” for side loading/dev work)