Going back to the original statement, I don't personally accept that deer have changed their habits i.e. from being diurnal and 'routine' feeders to crepuscular/nocturnal, specifically as a response to/because of some advancement in man's advances in technology (in this case uptake in use of improved/optical sights); if they do change behavioural patterns in certain areas (not a universal phenomenon, I personally tend to stalk just as many deer during the daytime as at dawn and dusk), then I would suggest this is mainly in response to human disturbance - be it hunting or otherwise eg traffic, and some cases they have even managed to adapt to the latter successfully and still follow largely diurnal/routine feeding patterns.
In the case of sporting stalking, 'the skill and the thrill's in the stalk, not the kill' , and thus we generally tend to enjoy sport not for its relative ease, but by our overcoming its perceived difficulties; one may stalk with his or her weapon of choice (irrespective of type - bow, rifle, crossbow, spear, etc.) according to ones own personal reasoning, and yet assuming an acceptable level of competency with said weapon within the range intended for its ultimate use, each can equally lay claim to a 'skilful' conclusion of their sport - the skill 'level' is ultimately determined by the individual's recognition of his/her achievement within these self-set parameters.
Numerous examples can be seen around the globe via internet videos and programmes where a variety of tools/weapons may be seen in use, including several, the use of which athough banned for the purpose by legislation in this country, nonetheless are demonstrably capable of getting the act done humanely when used in skilled hands. It should also be borne in mind that it is just as easy to wound an animal with a poorly placed rifle shot as it is a poorly placed arrow or crossbow bolt, and indeed many argue that the 'suffering' of any quarry species unlucky enough to be wounded by shotgun or rifle bullet fragments may be argued to be greater than one wounded by a misplaced arrow; that may or may not be the case, and can be argued upon at some length and indeed to little decisive conclusion, but the main determining factor still remains the combination of competence, confidence, self-discipline and ability - the skill- of the hunter.
How skilful one decides one wishes or determines to be is of course a personal decision; one man may ascribe skill to a long rifle shot successfully pulled off, another may find satisfaction in crawling as close as possible to his intended quarry before thinking of ending the stalk, be this with a photograph via a camera, footage with video, a pleasant memory otherwise unrecorded, or a careful shot from his weapon of choice.
Similarly, his or her choice of equipment to assist them in their sporting pursuit is down to each individual, there being no universal right nor wrong in such chosen items. We tend these days to use binoculars and sights to facilitate recognition, selection, shot placement etc. all as part of the beginning and end game of our pursuit, but the actual act of the stalk (practised to the aforementioned successful conclusion) is still where the skill truly lies.