According to the article:
Quality: Although the quality of streaming video has improved over the years, it is still dependent on the viewer’s broadband speed. Unfortunately, not all consumers have access to or can afford the internet speed that will deliver the best possible quality.
Using Disney+ as an example, an internet speed of 5.0 Mbps is the minimum required for HD content, while 25.0 Mbps is for viewing 4K UHD content. Other streaming services have similar requirements.
Although standard definition DVD quality can be easily provided to most streaming viewers, physical 1080p Blu-ray supports transfer rates of up to 48 Mbps, and UHD Blu-ray supports transfer rates of up to 128 Mbps. The only streaming service that can support more than 40mbps is Sony Bravia Core which provides up to 80mbps. However, that is only available to owners of select Sony Bravia Smart TVs. Disney+ and Netflix are nowhere near that level yet.
This means that streaming services have to use sophisticated compression techniques to try to deliver equivalent quality to their subscribers despite low transfer speeds. However, they don’t necessarily reach that goal.
So if they're going to take away the physical medium, they'd better up their game on the streaming end. I've always noticed the downgrading of video and audio quality through cable compared to disc playing. I'm stuck with Spectrum cable.
All the best,
Nonoise