It’s not even clear that Fallout 76 will have mods, in the traditional sense - as an always online service, the options are going to be more limited and the items Bethesda wants to sell (if any) could prove more cosmetic. If Bethesda wants to create a version of Creation Club for Fallout 76 and market it to gamers, using its own service may be the most effective way to do that.
And few modders have a means of making any money on their creations that are compatible with the base work being the property of the original studio. But it’s often easy to steal work, credit is slipshod and haphazardly assigned. Some mods for some games are so well-executed and constructed that they absolutely deserve to be treated like paid content, as far as the quality of the work that went into them. But the problems related to modding are difficult to solve.