Yes, synthetic sleeping bags can be just as warm as down sleeping bags, and they have some advantages over down. While down is an excellent insulator, it has one major weakness: it loses its insulating properties when wet. This means that if you get caught in a rainstorm or accidentally drop your sleeping bag in a stream, your down sleeping bag won't keep you warm. Synthetic insulation, on the other hand, retains its insulating properties even when wet, which makes synthetic sleeping bags a better choice in wet or humid conditions.
In addition, synthetic sleeping bags are often more affordable than down sleeping bags, which makes them a great option for budget-conscious campers. They also dry out more quickly than down bags, which means that if your bag does get wet, it will dry out faster and be ready for use sooner.
Another advantage of synthetic sleeping bags is that they are generally easier to care for than down bags. They don't require as much special care and storage, and they are less likely to be damaged by moisture or compression.
While it's true that down sleeping bags are generally more compressible and longer-lasting than synthetic bags, the warmth and reliability of synthetic insulation make synthetic sleeping bags a great choice for many camping situations. So, if you're looking for a sleeping bag that will keep you warm and dry without breaking the bank, consider a synthetic sleeping bag.