What causes ageism to exist to this day?

One of the reasons ageism exists is because of culture. We are living in a youth-obsessed world. The rise of technology has led to hiring biases. Many companies think that younger people will be more tech-savvy. The other reason for ageism is that most companies do not understand that older workers own a lot of knowledge and experience, which is worth paying. The screening algorithm automatically disqualifies you because of your age in most online jobs.