I agree. Even with RDL’s there comes a point for some where your ability to grip the bar and hold onto it for multiple reps might give out before you can provide an overload to the hams/glutes/erectors.
I advise my athletes to go without straps until they are truly necessary but not before-the same for various pulls: mid-thigh, counter movement shrugs, or clean pulls (usually not necessary due to the intra-set RI/cluster). For those who have even a month or two of such experience with RDL’s they know when they need them. Over time, they begin to try to go without them for even heavier loads but eventually there is usually a point where they are needed.