If she had appeared 30 years ago, we would have known only about Lana Del Rey, and Lizzy Grant would never have existed to us.
The problem of millions of uninsured has existed in this country since—well, since forever.
It existed in humans, under the name of Takotsubo cardiomyopathy.
c.1600, from French exister (17c.), from Latin existere/exsistere "to step out, stand forth, emerge, appear; exist, be" (see existence). "The late appearance of the word is remarkable" [OED]. Related: Existed; existing.