More or less, yes. The set bonuses from DT gear isn't useless and a source of 6* gear is always nice to have, but given what resources you need to be able to actually farm hard DT it's somewhat lackluster. FW, at least in my experience, allows you access to 6* gear long before DT hard is a realistic farming option. Farming dungeons likewise. Dragon 24 has nothing on DT hard, which both takes me much longer and in many cases won't allow me to auto it.
The only material I actually farm in DT is the aforementioned magma cores, not because I desperately want fatal gear, but because it's the only boss that I can beat quickly on auto at this point. Even then, the amount of legendary material I get out of it is very limited. Even after several rotations of pretty much farming the magma cores exclusively, I still can't forge more than about 50 pieces of 5-6* fatal (of which most will be sold anyway). For every piece of fatal gear I can use, I'll likely get several pieces from other non-DT sets that are equal or better.