Most girls don't seem serious about dating, but say they want a relationship, need some insight and advise.

I've dated about 20 girls since November. Only three of them seemed to care and put in effort to communicate and go on dates. Most of the relationships fizzled out after the second or third date. I genuinely look forward to seeing them and spending time together, but it seems like most of the girls don't share the same enthusiasm. They often don't try to make plans or just flake, even though there seems to be chemistry and they appear to enjoy our dates. Why doesn't my effort or excitement get reciprocated, even when the dates seem to go well? Why do so many women flake?