Moog track bar does not come with the poly bushing, you have to put that in. Other than that you had an impressive list of things you replaced, but, when you say you f eel it right under the seat , that sounds to me like ball joints. Or wheel bearings. Did you lube the driveshaft splines?

I replaced all 4 front ball joints already so it’s not those. Front driver wheel bearing has also been replaced, passenger side has no play when I jerk on the tire.

I have not lubed the driveshaft splines - would that be causing this much vibration? I would think it would have to be seized in order to cause this.

The trackbar is supposedly the No1 cause of a shaking issue, and in my opinion must be good in all respects, there is no way it can be allowed to have movement, damaged mounts, or wallowed bolt holes under any circumstances

Easy to check ball joints, and "I did them already so it's not that' isn't good checking.
Wouldn't it be easier to replace the hubs than replace the wheel bearings? just saying. So, this is a safety issue, you need to get under that thing while somebody turns the wheel and look for play. Then jack it up and do it again. Then use a pry bar under the tires to check for movement, yes even in the trackbar mount. As stated, any part of the trackbar loose will cause it, esp the factory bushing where it bolts to the axle. Also if the axle side mount is cracked where it's welded on, or if the mount hole is wallowed out, very common. I always replace the stock track bar bushing with a Poly bushing, which is a job in itself but if you don't you will have play there. All tie rod ends are in play look at them very carefully. Jack it up and shake the wheels, look for movement. Look at the frame, for rot, anything thats going to cause looseness. Make sure the back axle isn't falling off. Make sure the wheels are tight. That is you and your passengers in there, so find the problem before it