Most of the things you've listed here don't actually seem all that reasonable to me.

User agents as a concept are rather poorly thought out across the board and not all that useful but persist because that's just how technical cruft is.

Fonts should be provided by the website; if not provided the choice should take the form of a spec sent by the website including line height, sarifs or not, monospace or not, etc. There's little to no excuse for the current font situation IMO beyond poor design decisions that became heavily entrenched.

Timezone and other obviously private metadata should never be shared without the user explicitly granting permission on a case by case basis. The status quo here is completely inexcusable as is the continued failure to fix the problem.

Size of the physical screen should never be exposed under any circumstances. The current size of the browser window is reasonable on its face but now that fingerprinting is understood to be an issue should always be heavily letterboxed unless the user consents to sharing the exact value.

Video formats should be provided by the website as a list of offerings and the browser should respond with a choice; the user could optionally intervene. There's no reason to expose the full capabilities to a remote service.

Querying the current time should be gated behind an explicit permission. There's almost never a need for it. However from a fingerprinting perspective you also have to worry about correlating the rate of clock skew across clients. That can be solved by gating access to high resolution time counters behind an explicit permission as (once again) the vast majority of services have no legitimate use for such functionality.