Nope. Good lenses and good TCs used properly work are still better than cropping IMO. Plus, you lose subject isolation when you crop vs using a TC.
However, it's also a case by case basis. As Geoff mentions, AF accuracy isn't as good with TCs attached so for tougher, more active subjects, it's sometimes better to crop. Especially if we're talking a 2X. I find that 2X TCs are only OK for action and I have much better success with them when the animal and I are stationary (you know, more or less LOL)
For whatever it's worth I think you are absolutely correct about the good lenses and good TCs being the proper solution. At the moment even though I own almost every Z system lens sold except the Noct and some of the wide angles and the super long lenses that I just don't have a use for. A 2x TC and 100-400 is cool enough in my world so I am tracking with you on that ultimately being the best solution. To me the 100-400 is the most perfect photography tool I have ever touched and a TC does absolutely nothing to degrade the experience except when the light gets low and even then it's just a matter of letting the Z9 computer go to work and start using electronic high ISO tricks to deal with the light issue.
My brain wasn't shifted into Z terms when I first responded and I wasn't thinking about how few of the Z lens even work with a teleconverter. Two lenses in my case, a 100-400 and a 70-200 and to me makes no sense to attach to a 2x converter to a 70-200 when there is a 100-400 sitting right next to it.
My cropping preference remarks kind of reflect the fact that I have the F3 button on my Z9 set to switch between FX and DX fields of view should I want to reduce the framing of what I am seeing in the EVF while composing. It works really well for me as a cropping in the field tool as opposed to pruning in post.
I should also have included one other key difference between Z teleconverters and using the DX option...$500 dollar per TC for a total of $1000 for the pair. $600 if you don't buy them at Christmas time on sale
Enough money to buy an ordinary amateur photographer a pretty cool Z lens for their camera that he or she could use every day or put towards the price of the proper telephoto lens that better meets their needs. With most of the Z lenses I use DX as the better option because it's the only option beyond using an FTZ contraption.
Here's a personal solution that sort of fits the original question that may also apply to at least a few others in the group who don't make their living shooting critters from a hundred of yards away every day. I shoot a Z FC DX body that weighs less than a pound. Often with the Z 100-400 and Z 70-200 lenses, sometimes with the 2X TC, and it is a perfectly balanced camera and lens combination that makes me happy that I left the Z9 at home on days when I can live without all the Z9 bell and whistle computing power and 2.5 extra pounds of weight
I bought the Z FC because slinging the Z9 around all day hanging from the fingers of my right hand was taking a major toll on my shoulder and elbow. The improved weight balance alone makes for reduced motion blur from shaking hands. With the FC and 100-400 the center of mass is in the center of the zoom ring and it balances perfectly cradled in my left palm even with the TC on the lens. When using the Z9 the center of mass is 2.5 pounds greater and centered over the camera battery in the body pulling the aft end downwards and it feels clumsy and awkward.
And if FC ends up not being enough camera for what I am trying to accomplish I break out either the Z7II or Z9, switch to full frame and take it from there. It's my opinion that very few people on the planet can see with the naked eye the difference between properly exposed and properly composed images from any Z body without seeing the data so I worry less about which body I am using and just have fun concentrating on taking pictures correctly with what's in my hand at the moment.
That way I'm still having fun, my photographs don't usually suck too bad and the photo world stays in perfect harmony
Happy shooting everybody.
