There are advantages and disadvantages to both.
Sugar flowers offer full control over size, shape, and colours – even colours that are not naturally occuring. It also allows for flowers that are out of season. Sugar flowers are handmade and take a lot of time produce and are therefore more expensive. However, with the recent rise in flower prices since 2019 the price gap has become smaller.
Cut flowers are a less expensive option but you are limited to what is available at the time of ordering. Fresh flowers can wilt over time so it’s a good option depending on pickup/delivery, event time, and cake setup location.