This is covered in the linked article, read around this quote:
> Moreover, not only does 21st Century Fox have a lot of content, it has content that is particularly great for filling out a streaming library: think The Simpsons, or Family Guy; according to estimates I’ve seen, in terms of external content Fox owns eight of Netflix’s most streamed shows
Yea, but they could invest in new content aside from 21st Century Fox... Netflix didn't build up their original content via acquisitions, they invested in content creation... Disney could do similar, especially with the various IPs they already control.
Sure, perhaps there's a difference to be drawn between "is in competition" and "is competitive".
Disney is currently able to _try_ to compete, but their new streaming service is not competitive due to a lack of content, and won't be for years if they try to build up their portfolio organically as Netflix did.
If they bought 21st Century Fox, then arguably they would be immediately competitive with Netflix.
This is a classic build vs. buy decision, where (regulatory concerns notwithstanding) it's often better to buy as a well-funded new entrant that's trying to catch up with an incumbent.
This is covered in the linked article, read around this quote:
> Moreover, not only does 21st Century Fox have a lot of content, it has content that is particularly great for filling out a streaming library: think The Simpsons, or Family Guy; according to estimates I’ve seen, in terms of external content Fox owns eight of Netflix’s most streamed shows