It's not their responsibility. For that part of the law, you need to get your lawyer involved. And your lawyer will probably tell you not to waste your money, because the way the DMCA was written makes it practically impossible to find enough proof to actually win.
I don't think the "internet is a series of pipes" politicians could've foreseen Youtube or TikTok, but had I believed that the authors of early internet legislation had that foresight, I would've accused the law of being intentionally written to lead to these implementations.