Basically any HTTP 301 response from an HTTPS request indicating a target redirect to HTTP should never be honored at all by any browser, those servers doing that are clearly violating basic security, or are severaly compromized.
However a 301 reply to an HTTPS request can still redirect to another HTTPS target (including on another domain, provided that other CORS requirements are met).
If you navigate an HTTPS link (or a javascript event handler) and the browser starts loading that HTTPS target which replies with 301 redirect to HTTP, the behavior of the browser should be like if it was a 500 server error, or a connection failure (DNS name not resolved, server not responding timeout).
Such server-side redirect are clearly invalid. And website admins should never do that ! If they want to close a service and inform HTTPS users that the service is hosted elsewhere and no longer secure, they MUST return a valid HTTPS response page with NO redirect at all, and this should really be a 4xx error page (most probably 404 PAGE NOT FOUND) and they should not redirect to another HTTPS service (e.g. a third-party hosted search engine or parking page) which does not respect CORS requirements, or sends false media-types (it is acceptable to not honor the requested language and display that page in another language).
Browsers that implement HSTS are perfectly correct and going to the right direction. But I really think that CORS specifications are a mess, just tweaked to still allow advertizing network to host and control themselves the ads they broadcast to other websites.
I strongly think that serious websites that still want to display ads (or any tracker for audience measurement) for valid reasons can host these ads/trackers themselves, on their own domain and in the same protocol: servers can still get themselves the ads content they want to broadcast by downloading/refreshing these ads themselves and maintaining their own local cache. They can track their audience themselves by collecting the data they need and want and filtering it on their own server if they want this data to be analysed by a third party: websites will have to seriously implement thelselves the privacy requirements.
I hate now those too many websites that, when visited, are being tracked by dozens of third parties, including very intrusive ones like Facebook and most advertizing networks, plus many very weak third party services that have very poor quality/security and send very bad content they never control (including fake ads, fake news, promoting illegal activities, illegal businesses, invalid age rating...).
Let's return to the origin of the web: one site, one domain, one third party. This does not mean that they cannot link to other third party sites, but these must done only with an explicit user action (tapping or clicking), and visitors MUST be able to kn ow wherre this will go to, or which content will be displayed.
This is even possible for inserting videos (e.g. Youtube) in news articles: the news website can host themselves a cache of static images for the frame and icons for the "play" button: when users click that icon, it will start activating the third party video, and in that case the thirf party will interact directly with that user and can collect other data. But the unactivated contents will be tracked only by the origin website, under their own published policy.