Why do people use I-beams?

Could you elaborate on the reasons why individuals and organizations choose to utilize I-beams in their construction projects? Are they solely driven by the enhanced structural integrity they provide, or are there additional factors, such as cost-effectiveness and ease of installation, that also play a significant role in the decision-making process? I'm curious to know if the versatility of I-beams, allowing for use in various applications, is another factor that contributes to their widespread adoption.