I must have missed that part when I blinked.
First,
HAPPY NEW YEAR TO EVERYONE (happiness, health and success to you, friends & families) !!!

to
φ of π's comment t but I can hardly contradict him/her because yes, the chemistry between Chakotay & Seven was really far from obvious, at least on the screen, especially compared to Chakotay's (flirty/seductive) attitude towards Janeway, Kellin or even Marla Gilmore.
As for Seven, she showed much more "passion" (at least for a human raised in a Borg environment, where feelings are repressed) in flirting, wether with Axum in Unimatrix & yes, even with Janeway herself, especially in some of their intimate scenes (cf to the equivocal body language from both actresses, even if it wasn't necessarily desired, especially according to the tense relmationship between Mulgrew and Ryan! -> I read that Bryan Fuller - & Brannon Braga wasn't against this idea, in itself - wanted to see Seven interested in female representatives and it would have been logical to see her interested in a strong personality as Janeway's one. Alas, Paramount studios and UPN's representatives dismissed the idea, believing that viewers weren't ready to see a lesbian romance to become).
Anyway. To return to C/7, for me, Robert Beltran & Jeri Ryan ensured the minimum service (I think their minds were already elsewhere: RB just wanted to have something to do than stting in a chair, saying "yes, Captain, no, Captain" and then, to see his character flirting with the well-turned pretty blonde wasn't finally so bad, regardless of the ins and outs. As for JR, she seemed not to care anymore about her character's fate) given the potential already shown with other actors (both have more or less admitted in interviews given afterwards that this romance was hardly understandable by themselves - and supposedly and logically by viewers too - because it just came out of nowhere => they never really made effort to defend it) and only those who want to see chemistry between them, can see it but hey, everyone is free to see things one's own way, right?!
Even if we can not undo what has been done on screen, amateur writers have
always the option of offering us another purpose or the same end but with more
development,
from the moment where characters are still alive. Alas, it's not always the case and no matter attemps from authors to re-write the scenario, nothing will change the fact that, in the case of a couple, whether good or mismatched, the end will be hardly correctable if one of the two dies, on screen, in road, right?! -> cf to Major Crimes and the shocking death of the major character, Cpt Sharon Raynor. Indeed, regardless, this event might not have too much consequence, but alas, the character was romantically linked to another one, Andy Flynn, and their lovestory (a long courtship of 5 years, which finally ended by a wedding in the first part of s6) was one of elements that kept us in suspense for several years. Sad & frustrating!

-> imagine the same if Cpt Janeway, Chakotay or Seven* (what was initially planned by Braga but refused by UPN, because of the character's popularity) had died suddenly in the last season... . It would have left a bitter taste in the mouth and re-watching the series, in particular the last season could be particularly unpleasant.