ELI5, what was the deal with the Internet Explorer lawsuit?

I feel like I'm too young to understand what happened here. Apparently, Microsoft got sued for including Internet Explorer with Windows, starting with 95. It was an antitrust lawsuit, and it had something to do with eliminating competition. Although I can see how that is, I still have one question: what other choices were there?

The Internet was becoming increasingly relevant during the 90s, and while some ISPs like AOL put you in their own walled garden, others gave you little to no software. You'd need some kind of browser, right? Even with how garbage IE was, it was better than nothing.