The question in the title comprised the entire question asked. There are advantages and disadvantages to all of these considerations and such considerations also depend upon application. You didn’t say what your particular application is, so that makes any answer I provide longer. (If you want short, pithy answers, ask detailed questions. ;o)
For example, if you are a bowhunter, most hunting regulations specify a minimum draw weight for hunting, typically 40# or so. Thus, a 30 pound bow would be illegal to use, a major disadvantage.
In general, hunters prefer higher draw weights and target archers lower draw weights. (As with all such broad statements there are many exceptions.) The reason for this difference is that a target archer may have to shoot one hundred or more shots in a single day but a hunter merely a handful. For some reason, a compound bow peak weight of 70# has proved popular for deer hunters. This is excessive as these bows will drive an arrow through the body of a deer, the most common large game animal in the U.S., and out the other side (still traveling at high speed). Possibly this very high draw weight is due to manhood issues amongst the bow purchasers or is possibly just a manifestation of hunters buying whatever everyone else has.
Olympic Recurve archer Brady Ellison shoots a very high 53# bow setup and is doing very well for himself. Most everyone else is shooting a lower draw weight, the women being typically about 10# lower.
In general and for target archers:
Positives of a Higher Draw Weight for Target Archers
A higher draw weight produces a crisper release of the string. (The string supplies the force to move the string out of the way and the more force available, the straighter the path of the string.)
A higher draw weight produces a flatter arrow trajectory. (This allows an archer to stay closer to perfect form for longer shots, not requiring as much bow elevation.)
Negatives of a Higher Draw Weight for Target Archers
A higher draw weight produces more fatigue. (Drawing a 70# bow is the equivalent to exercising with a 70# weight. How many repetitions can you do and execute with the same form on your last shot as you had on your first?)
A higher draw weight produces more tension at full draw. (Even compound bows suffer from this effect: a 70# bow with 65% letoff still has 25# in hand at full draw. A higher “holding weight” shortens the amount of time an archer has available at full draw and stresses the full-draw form of the archer. Obviously a recurve or longbow archers has an even higher load at full draw.)
In the past, high draw weights were the only option to increase the power and cast of a bow. Many of the English bowmen of the past were shooting bows of 100#-125# of draw. But that was then and this is now. Now, lightweight and extremely stiff carbon arrows allow high arrow speeds to be produced at much, much lower draw weights.
So, unless you have aspirations of being a very, very serious target archer (one who trains many days a week) my recommendation is to consider the goal of finding the lowest draw weight bow that will allow you to shoot your last arrow in any set with the same form and execution as you had on your first. Higher draw weights than that require serious physical training to be successful (which can be achieved by shooting, but that means many days per week of shooting).
“My recommendation is to consider the goal of finding the lowest draw weight bow that will allow you to shoot your last arrow in any set with the same form and execution as you had on your first.”
The overwhelming popularity of compound bows in the U.S. is driven by the difference in peak weight and holding weight of those bows. Low holding weights lower strain on the archer at full draw and increase the time available to aim while providing high arrow speeds because of he high peak weights. But too high of a peak weight will wear a compound archer down in a longer competition, resulting in mistakes that cause point losses no one likes. The same is true for recurve and longbow archers.
Choose wisely. The worst thing that can happen to an archer is to be overbowed (too much draw weight) because it distorts form and literally sucks the fun out of shooting.