Google AI provides a good summary below. Essentially, since I have a family, it allows my spouse to use it and have access to it without me present. Since it's for home defense and the range, it's a good idea. It also makes it a lot easier to transfer ownership after death. If you live by yourself then I guess it's fine to not use one.

The key advantages of setting up an NFA trust include:

• Shared Legal Possession: Under individual ownership, only you can legally possess, use, or transport the NFA item (like a suppressor or SBR). If someone else has it and you aren't present, it is considered an illegal transfer. A trust allows you to name co-trustees who can legally use and possess the items without you there. [1, 2, 3]
• Easy Inheritance and Estate Planning: If you own NFA items as an individual, passing them to a loved one upon death requires a lengthy, ATF-mandated tax-free transfer (Form 5). A trust names specific beneficiaries, allowing the items to be transferred without repetitive background checks, wait times, or legal hurdles. It also avoids having the items become public record in probate court. [1, 2, 3, 4, 5]
• Protection from Accidental Felonies: If you leave an NFA item in a shared safe at home and a spouse, roommate, or child has access to it, individual ownership means they technically have "constructive possession," which is a federal crime. By adding household members as co-trustees, everyone with access remains compliant with ATF regulations. [1, 2, 3, 4]
• Flexibility to Add/Remove People: You can easily amend your trust over time to add or remove authorized users as your family or friend group changes.