The reality is that the counter-notice process can leave content down for two full weeks. This means that a DMCA takedown can be used to silence important, time-sensitive information. Imagine there's an upcoming referendum on some major issue. The party with more lawyers can send DMCA notices to all the sites, YouTube videos, etc. opposing their view of the referendum a week before the vote, preventing voters from obtaining critical information.
FWIW, a counterclaim on YouTube took about two hours to process when I had to do one due to an incorrect DMCA claim. That may not be representative, but it was pretty quick.
It's certainly possible that actions like those you outline (which essentially amount to barratry) could happen. I never said that the content provisions were perfect; I'm not a big fan of some language and some behaviors that are in the content takedown sections of the DMCA. It could certainly be modified and improved, and I'd be all for that. But I'd argue that it, as-is, remains a useful course of action for the "little guy" IP producers who essentially have no other recourse, and that that outweighs the abuses perpetuated by a small group of content creators.
The reality where hosting companies and ISPs cave immediately to the side that has more lawyers. The reality where companies spray DMCA takedowns to intimidate lone hackers they dislike, in situations they would never dare actually take that person to court under. The reality where large companies form backroom deals to "streamline" DMCA takedowns so that dissident voices can be silenced with a keypress, limiting exposure.
"That reality? Because you're not entitled to your own."
That reality? Because you're not entitled to your own.