Baudrillard died in 2007, before social media fully arrived. But the thinkers working in his tradition argue that he was describing something that the social media era has simply pushed to a new level of intensity.
The curated self of Instagram is a pure simulacrum in Baudrillard's sense. There is an original, the actual person living their actual life. But the Instagram self is not a representation of that original. It is a construction that becomes the reference point: people begin to live their actual lives partly in order to produce the social media representation of those lives, and the representation becomes what is experienced as real by both the producer and the audience. The holiday is lived partly so it can be posted. The meal is photographed before it is eaten. The experience is performed for documentation before it is had as experience.
At a more political level, the attention economy operates precisely through the logic Baudrillard described. Political reality, as experienced by most people, is the reality of social media feeds: algorithmically curated, emotionally optimized, maximally stimulating constructions that bear a complex and often distorted relationship to whatever is actually happening in the political world. The rage and fear and tribalism that characterize contemporary political life are not responses to actual political reality. They are responses to a simulation of political reality that has been designed, by the architecture of the platforms and the economic incentives of their operators, to maximize engagement.
Baudrillard would note the deepest irony: the people who are most confident that they have seen through the simulation, that they know the real truth behind the mainstream media illusion (whether on the right or the left), are often the most thoroughly captured by a simulacrum. Conspiracy theories are hyperreality par excellence: constructions in which the simulation is felt to be more real, more coherent, and more meaningful than any contradicting evidence from the world itself.
The criticisms of Baudrillard are serious and worth engaging with. Christopher Norris argued in Uncritical Theory (1992) that Baudrillard's hyperreality thesis is self-undermining: if everything is simulation, then his own analysis is also a simulation, and has no privileged access to the truth about hyperreality. More concretely, critics argue that the thesis is seductive but vague: at what point does representation become hyperreality? Every representation involves selection, framing, and construction. Baudrillard gives no clear criteria for distinguishing normal representation from the pathological case he calls hyperreality.
These are fair criticisms. The most defensible version of Baudrillard's argument is probably not the sweeping metaphysical claim that reality itself has disappeared but the more specific sociological and political observation: that in media-saturated societies, the mechanisms by which media representation shapes, amplifies, and in specific cases substitutes for reality are systematically underestimated by the people subject to them, and that this has serious political consequences that critical theory should take seriously.