Given what we've seen of how people can behave online, it's probably good and almost certainly necessary that some protections exist for platforms and internet service providers. That's not to absolve the likes of, say, Facebook from moderating what's posted on their site, or taking steps to prevent the violation of laws on the part of users to a reasonable degree; it's simply to note that even with the best efforts of these companies (which, to be clear, we almost certainly aren't seeing) there's not much to be done should people decide to do whatever they want, rules be damned.
What protection exists for platforms is limited, as evidenced by a recent case involving a hip-hop streaming site and some of the biggest music labels in the industry. Spinrilla, the site in question, was found liable for copyright infringement in a Georgia federal court after the Recording Industry Association of America (RIAA), on the part of Sony Music, Warner Bros,. Atlantic and LaFace, pursued a copyright complaint against the service. Spinrilla's nominal mission is to provide a platform to independent hip-hop artists, which would certainly suggest that the site aimed to only have works uploaded that belong to the uploading artists, but, as is the nature of streaming free of onerous levels of oversight, Spinrilla apparently became home to pirated, unlicensed works from other artists — 4,082, according to the RIAA.
Typically, sites like this that stream music or video are protected by the DMCA Safe Harbor provisions, which hold streamers as not liable for copyright violations committed by users. But those protections are granted provided that sites make certain efforts to prevent infringement, or provide means to address violations and remove the infringing content. In this case, Spinrilla didn't meet those standards; per Billboard, the site had neither a policy for repeat infringers nor a designated agent to handle takedown requests. So while Spinrilla and others sites can say the right things about safeguarding against infringement, there has to be actual resources behind those words if they hope to avoid liability.
Given the work required, it's no wonder that we see hegemonic powers in the streaming world; licensing content is an expensive proposition, and relying upon user-generated works can be equally demanding of time and expenditure if you're doing the requisite work to maintain DMCA protections. Perhaps Spinrilla bounces back, or perhaps they learn that going up against the likes of Spotify or Apple Music requires you make no mistakes, and even then you might find yourself on the losing end.