“Where in the Torah does it say an excuse not to get married because the guy is 20 -30 years older?”
Where in the Torah does it say that women are required to get married?
It is common sense that a person should marry someone appropriate for them. For many girls a 20 year age gap is almost certainly inappropriate. It is not being “picky” to want to marry someone approximately your age.
In the same families, brothers will have long lists of girls read to them and will be able to go out whenever they feel like it. Girls will have one or two boys on their list and will often have to go months between dates.
“Andectodal evidence” is evidence (it’s right there in the name). It’s normally not as strong as statistical evidence but in the absence of statistics to the contrary, it can be very strong.
Furthermore very strong anectodal evidence will often trump statistical evidence to the contrary. If someone came out with a statistic that 68% of chickens can survive a week without a head, that stastici would rightly be laughed off in the face of the anectdotal evidence that chickens without heads cannot survive more than couple of minutes.