Let us go to photography. If you magnify an excellent photo, it will be bigger. My playback on the 2 track is "bigger" than the original, also the electronics in the reel have been upgraded. The playback is equivilant to an equipment upgrade. Is "bigger" better?
a bigger soundstage would generally considered to be better. and i would say that when there is a sense of presence and ambience (and room energy) that happens right before the music starts, that is an aspect of soundstaging that is always better. but sometimes you get an elongated or stretched soundstage, a 'U' shape, or maybe a 20 foot wide piano....so there are cases where a bigger soundstage is not better. better is better. and more real is better. but much of that is very subjective and system dependant. some would say live music does not 'stage' like recordings can.
your photography analogy is a good one. magnifying a photo does make it larger; but if the resolution and clarity of the photo is not sufficient then the magnification loses the sense of reality. the question is 'what is right?'.
getting back to how your RTR might be better; it could be as simple as the analog output on your tape deck could synergize with your preamp better than your phono stage. i have no idea of that but it's possible it's a signal path issue and not a format issue. or it could be that your tt/arm/cart/phono stage are not as high quality as your tape deck.
my point is that when you make generalizations as universal truths about recording Lps onto tape you need to consider whether it applies to some, or to most, or to all cases and qualify it; or guys like me will come along and call you on it. i have no doubt you are hearing what you are telling us. but exactly the implications of that is in question.