Yes, there is now a limit in the use of ba drivers that was reached 5 years ago. They give lots of detail, but dry, boring, lacking soundstage, lacking frequencys sound. This is a problems what manufacturers are trying to solve in top models. The trick is that drivers account for about 30% of the sound. Another 30% is crossover, and 30% tuning. Some models are even using dampers instead of crossover, because bad crossover can kill all the details in sound.
Most headphones that cost more than 1000 euros offer innovative technologies and a complex crossover. It is clear that there is a lot of marketing here, but open ba, beryllium, bone conduction, est, it all makes a huge difference and costs money.
My recommendation is Unique Melody MEST MKIII. I am realy in love with them.
I also have Monarch MK2 and SoftEars RS10 at the moment. I tried Fir Audio and 64 audio and both Monarch and Mest are much better, so nothing interesting there.
You should try something from Unique Melody with bone conducting drivers. This is realy different feeling of sound. Extremely wide soundstage and top realism.
Also IMR are realy interesting. The best bass I ever heard is IMR RAH.
Also recommend to buy some expensive planar and dinamic driver iem. A lot of new technology happening there in the moment.