The easiest and most common answer to that question is this: "If Bilbo had not lost his matches, he wouldn't have found the One Ring."
In chapter 5, Bilbo wakes up after hitting his head and being knocked out. He does not have any matches, so he is forced to fumble around on all fours. During this process, his hand brushes up against something metallic. The One Ring! Bilbo has no idea what it does, but he does put it in his pocket. Soon after, Bilbo accidentally slips the ring on while Gollum is confronting him. Gollum assumes Bilbo is leaving the cave, so Gollum takes off after him. Bilbo follows Gollum in order to find the way out. Thank you ring of invisibility.
I don't wholeheartedly jump into the "he found the ring because he lost his matches" mentality. Yes, it makes sense. Yes, I can see it. But it's equally possible that Bilbo wakes up, discovers that he is in total darkness, lights some matches while trying to find a way out, and sees the ring. All the reader knows for sure is that Bilbo didn't have matches and found the ring in the dark.