You're still just focused on technical implementation and not the intent behind actions, which is also important and will likely be considered by the courts.

While there is no technical difference, there is quite a difference of intent between watching a streaming video and downloading it to circumvent copy-protection.

Unsure if that can be configured or not, but if your video content distribution network can’t rate limit or handle bursts you probably have more pressing issues.

It doesn't matter. YouTube's Standard License authorizes certain videos to be viewed only by streaming through YouTube's web player or an authorized client. This is enforced by obfuscating code in the player. By circumventing that code, youtube-dl veers into "illegal piracy tool" territory.

Note that it wouldn't matter if youtube-dl contained no deobfuscating code at all, but merely downloaded and evaluated the JavaScript Google's web client uses to deobfuscate. The result is the same: youtube-dl circumvents copyright access controls and is therefore illegal.

The Betamax case predates the DMCA, which created the “anti-circumvention” laws the RIAA is relying on here. It was also a 5:4 decision that depended on “a significant likelihood that substantial numbers of copyright holders who license their works for broadcast on free television would not object to having their broadcasts time-shifted,” and the copyright holders’ failure “to demonstrate that time-shifting would cause any likelihood of non-minimal harm to the potential market for, or the value of, their copyrighted works.” The opinion explicitly did not cover pay TV, and the court also noted that the cost of Betamax tapes made it difficult to build your own library of tapes for repeated viewing, in concluding that there was no likelihood of harm. I think it’s an interesting and open question whether the typical use of youtube-dl falls under fair use.

also: https://en.wikipedia.org/wiki/Private_copying_levy