Black holes have a temperature and will eventually evaporate completely
In 1974, physicist Stephen Hawking theorised that black holes emit radiation due to quantum effects near the event horizon — pairs of virtual particles are created, one falls in and one escapes, effectively meaning the black hole slowly loses mass. This "Hawking radiation" gives every black hole a temperature inversely proportional to its mass. A stellar-mass black hole has a temperature of about 60 nanokelvins — far colder than the cosmic microwave background. A black hole the mass of the Sun would take 10⁶⁷ years to fully evaporate.
Objects defined by the fact that nothing escapes them are slowly leaking radiation and will eventually disappear entirely — they just take longer than the current age of the universe to do so.
“Black holes slowly evaporate. It takes longer than the age of the universe — but they don't last forever.”