For normal consumers...
Netscape -> IE monopoly -> explosion of choices
Email provided by your employer or ISP -> explosion of choices
IBM & Apple computers -> explosion of choices
Intel processor monopoly -> ARM computing explosion of choices
Kodak, majority of the film market -> explosion of camera choices
Tight music label monopolies + radio & store distribution -> explosion of cheap consumer choices for streaming vast amounts of music. No longer do you have to spend $20-$25 in adjusted 2018 dollars to buy an album with two songs you want to hear.
ABC, NBC, CBS, limited tightly controlled broadcast platforms with very regulated content -> endless array of media start-ups online, streaming choices, news sources
Playboy & similar, nearly your sole porn option for decades, highly restricted distribution -> seemingly infinite porn online from thousands of large sites
Information broadly, from limited, tightly controlled research options, difficult to access (if you can at all depending on your location) -> explosion of research options online, at a click, practically at zero cost
Limited publishing options, from almost nothing for the common person -> dozens of easy, inexpensive ways to publish text/audio/video and reach an audience. For $5 per month I can easily serve up video on my own site, host my own blog, post my own music, whatever.