The primary difference between the two approaches (and other approaches, like weekly or monthly) is in how they align with both your workers' and your company's cashflow.
Months, of course, vary in length. If your company is a restaurant, you make money per day. If you're an apartment complex, you make money per month. So from a business perspective, it's often optimal to align your payroll with how it evens out your cash flow.
The same applies to your workers. If they tend to have more monthly bills they'll prefer semimonthly, and if they tend to live more hand to mouth and have fixed-time expenses they'll prefer weekly.
This is somewhat tied to general wealth level in the first place. Someone who has a monthly car payment, and house payment, and private school payment - they have to pay those whether it's a 28 day month or a 31 day month. So they want the same amount of money per month to align with that. So they prefer something tied to the calendar month (semimonthly, monthly, etc.). Even if the "monthly" pay flexes to represent the right number of days in a month, the cadence is still optimal. Even when payday falls on a weekend, usually the payday is moved up or back in the same way that payment due dates are.
Someone who doesn't, who is just buying food and gas and whatnot, they need the same amount of those things per day. So a biweekly pay schedule, or a schedule otherwise tied to the day (weekly, etc.) are optimal for these folks. Also, these folks tend to be lower compensated, so the differences between the two schemes is more keenly felt.
Many places will pay hourly workers biweekly and salaried workers semimonthly on the pretty good assumption that the higher level/better compensated employees fall more in the former category.