The idea has been brought up a few times, and has been a slumbering discussion in the community for a long time. But admittedly, there’s been limited discussion of it here on the Governance forum.
See also here: Introduce discount on fees for holding/staking GMX
There are good arguments for staked GMX enabling trading fee discounts, particularly around boosting customer loyalty and helping retain larger traders. And a few good arguments against it as well, particularly around it adding complexity, and GMX being a neutral protocol that offers traders of every size a level playing ground with equal fees.
I lean towards the former side myself;