I dont know if you could share my thoughts. 
 When i fly with BEyondAtc, FSLTL, FSHUD… I find that the airports are lifeless when arriving at them.
This doesn't happen when I'm going to take off. but when I get to them on final approach, there are no planes doing Taxing or Holding short etc.

it is as if the machine didnt work to inject life on airports. So sky is good, but nothing down there. 
 

even arriving at JFK, or LFPG… no condensed traffic, no rows or pushing back. 
 

all that is only when taxing to runway and beggining my flight, never when arriving. 
 

 

Up your IFR aircraft amount in FSLTL and get GSX.  Then you'll have the problem of bad performance. Hopefully, BeyondATC can fix this but from what I am seeing I'm not hopeful. 

I have actually been pretty happy with the FSLTL, GSX, Beyond ATC.  Only problem is FSLTL treats me like I don't exist so I have to kind of sneak out in-between airplanes.  Luckily, MSFS does tell airplanes to hold during taxi but noting on take off or landing.  FSLTL also has a nasty habit of spawning an aircraft very close as soon as I'm on final.  Luckily it has the remove traffic near me option.  If they could keep spawning weirdness to a minimum, it would go a long way to being more realistic.  This is why I am not that excited about real world air traffic.  PSXT is real time based and it acts very weird, air planes just stop in the middle of the taxiway then don't move for a while, they go down the runway sideways, they disappear and respawn,  sometimes they are off in a field. Sometimes they land short or long.  The AI problem is a complicated one.

I think it will still be quite some time or maybe never where ground and air traffic and associated air traffic control act realistic. 

One day I'm hoping for spacing vectors and proper speed call outs and tight traffic.  Today flying into Denver we were landing on 16R and I could see an airplane below us just took off from 25,  and when we made the turn toward the runway I could see one airplane about to land one in the pattern making it's turn and then us spaced about the same.  They we also running 16L and 16 L had 2 airplanes spaced equally and 17 R had 2 airplanes on final. I could see airplanes lined up and taking off on 8 and 17L.  I'm not sure we will ever get to that level of immersion and realism with ATC and AI aircraft in Flightsim.