In this modern era, mostly people are being married in their third decade of life due to financial independence and more mature mind set instead of marrying in their younger age group. I completely agree with the notion and discuss about same in following paragraphs.
To commence with, people in their thirties are having stable financial ground. To elaborate, individuals are mostly earning in their middle age group and capable of sustaining good life and provide better living for their families and children, moreover, raise their offsprings to greater level in terms of study and health. People in late twenties do not need to depend on their parents and siblings, hence, seem to be a practical reason for not marrying in twenties.
Secondly, later age group people tend to have more developed mind set. Individuals are having their own preferences in choosing their better half. For instance, in U. S. A most people do assure their competence with respect to their life partner before getting married as it is a significant decision for spending entire life with each other. Therefore, sense of maturity is an important consideration in thirties to be in martial relationship.
In conclusion, I believe it is imperative to have developed perspective and stable financial equation which both are lacking in youngsters. The reason why people choose to be in relationship of marriage in late twenties. 
In this modern era,  
mostly
  people
 are  
being married
 in their third decade of  
life
 due to financial independence and more mature mind set  
instead
 of marrying in their younger age group. I completely  
agree
 with the notion and  
discuss about same
 in following paragraphs.
To commence with,  
people
 in their thirties are having stable financial ground. To elaborate, individuals are  
mostly
 earning in their middle age group and capable of sustaining  
good
  life
 and provide better living for their families and children,  
moreover
, raise their  
offsprings
 to greater level in terms of study and health.  
People
 in late twenties do not need to depend on their parents and siblings,  
hence
, seem to be a practical reason for not marrying in twenties. 
Secondly
, later age group  
people
 tend to have more developed mind set. Individuals are having their  
own
 preferences in choosing their better half.  
For instance
, in U. S. A most  
people
 do assure their competence with respect to their  
life
 partner  
before
 getting married as it is a significant decision for spending entire  
life
 with each other.  
Therefore
, sense of maturity is an  
important
 consideration in thirties to be in martial relationship. 
In conclusion
, I believe it is imperative to have developed perspective and stable financial equation which both are lacking in youngsters. The reason why  
people
 choose to be in relationship of marriage in late twenties.