Ignoring budget........I'd never go back to mechanical. Caveat, I tend to ride bikes with lots of hidden cables. Meaning any re-cabling of mechanical is a nightmare. Furthermore, complicated hidden mech routing can tend to make what should otherwise be great mech shift kits feel kind of crap. Think mech on a super aero bike with hidden everything. That's a non issue for electronic.

For an exposed cable round tube bike, it's a bit more irrelevant to me personally.

But, barring budget, yeah, I'd never go back to mechanical at this point.