This is a follow-up of MDL-78532, I think it would be worth it to create another one (core_reportbuilder_can_view_system_report) just performing the permissions check:

$report = system_report_factory::create($source, $context, $component, $area, $itemid, $parameters);
$canview = $report->can_view();

We might need this to allow external systems, such as the mobile app, to display links to reports a user does not have permission to see.