Does a Full Service Truly Restore a Watch's Movement?

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Hello fellow watch enthusiasts,

I'm currently contemplating the purchase of a pre-owned 7 year old TAG Heuer Carrera Calibre 5 (2017) from a professionel seller, that has undergone a full service, and I'm eager to gather insights from the community about the restoration process. Specifically, I'm curious about whether a full service genuinely restores a watch's movement to its original condition and whether the performance is comparable to a new watch.

Here are the details of the watch I'm considering:

Watch Details: TAG Heuer Carrera Calibre 5 from 2017

Maintenance: Fully serviced (450Euros), including replacement of the sapphire crystal(181.50Euros), metal bracelet(302.50Euros), and polishing(79Euros). This was done 1 year ago - the watch hasn't been used since.

Price: The seller is asking for 1700 Euros, down from the original listing of 2000 Euros

Condition of Movement: Does a full service truly restore the movement to its original condition? A full service of a watch involves disassembling, cleaning, inspecting, replacing worn parts, reassembling, lubricating, regulating, and testing the timekeeping accuracy of the watch. I'm curious to know if whether the performance of a fully serviced 7-year old watch is comparable to a new watch.

Value Proposition: Considering the maintenance history and age of the watch, do you think 1700 Euros is a reasonable price? Would it be a better decision to spend the same amount on a newer watch from let's say 2022 that has NOT undergone any servicing, maintenance or replacement of sapphire crystal, metal bracelet, and polishing as the 7 year old watch has

Effects of Inactivity: Given that this 7-year-old watch was fully serviced a year ago but has not been used since then, what impact does this inactivity have on the watch? I've heard that when a watch is standing still for a long time, it can dry out and potentially require servicing again.

Thank you in advance for your input