Safari crashes while streaming high bitrate videos

I use Safari mainly to watch videos on streaming platforms. There has been, however, issues when playing either high quality HD or 4K files: Safari complains about too much memory being used and crashes while playing the video.

This is happening, mostly, with Disney+, and after a few minutes.

Apple TV+, when used with Safari, is also crashing the tab (and yes, I know I can use the dedicated Mac app - I ran it on Safari specifically to check if it was the platform's problem or the browser's problem, and other streaming platforms don't have dedicated apps).

This has been an issue for the better part of a year, but now that I've tested it with Apple TV+, I'm pretty sure it's the browser's fault. Looks like it's a feature to prevent RAM leaks on web pages, but the streaming websites are doing exactly what they're supposed to do. and are getting caught in the middle.

Other browsers only load videos in 720p (WideVine limitations), which look pretty bad in a high-DPI monitor (such as MacBook Pro's).

MacBook Pro 16'' 2019, macOS 11.5.2, Safari 14.1.2.