Well quite apart from the fact that overnights are a required part of the job...and if you want to earn reasonable money and fly larger aircraft you have zero choice...they can be as good as you make them.
I will preface what follows with the fact that I am lucky...my airline doesn't have daily flights to many of our destos so we actually do get enough time, usually, to actually get out and about.
I have just returned from a BNE-AKL flight where I got 2 days in AKL, and caught up with an old mate from PNG days who I haven't seen in 10+ yrs...and 3 days (not including a 1/2 day at each end of those, i.e. arrived 1130LT departed 1300LT) where I caught up with 4 different mates and their wives in BNE. I could have also taken my Bonanza for a fly in BNE but just didn't get around to it. In AKL I was taken out to Dairy Flat aerodrome for a poke around and then to a aircraft restoration business, that belongs to friends of my mate, where I got to poke around a MK 16 Spitfire, Meteor, P40, Hawker Hart and a bunch of others...and an invite when next in AKL to have a fly of their Piston Provost.
When I get Sydney flights I catch up with my brother and his wife/kids, Father etc. In Dubai I usually have at least a lunch and often a few beers with mates in Emirates, In London I catch up with mates and usually end up out at White Waltham for a few beers and watch people coming and going in Tiger Moths etc...probably get a go in his C180 again soon. In Bangkok...well I am a single dad so I often misbehave in BKK
...in Perth I catch up with mates from my PX and NJS days. Frankfurt is no fun at all because 1/. no old mates and 2/. our HOTAC is 16km out of town...and Frankfurt is boring anyway...so I go for a walk or if it's snowing stay inside and be bored waiting the bar to be opened and have a few cleansers with whomever I am flying with...yet to fly with someone I won't drink with though I am developing preferences
Life could be a LOT worse...I might be working for Emirates where every RON is min rest...and all you do is sleep and then crawl back in the jet feeling crap. Same with Dragonair according to mates there...pity we only ever turn around in HKG or there would be some serious games of beer there
I spent years...read decades...avoiding long haul and now I am quite enjoying it.
And I have 5 days at home with my daughter before heading off to LHR via Dubai each way...then race down to BNE for the Talair re-union and then a week + more leave after that at home with my daughter before 7 days in Dubai with a few Jeddah shuttles in between beers with my Emirates mates....again.
Life is not too bad at all....what you make of it really. While I fully accept that long haul will wear thin in time I am 43 now and I reckon by the time it does I'll be about ready to hang up the full time wings anyway. In 10 yrs or so I might dust off the UK residency rights and pull my finger out on the pommy ATPL (just two exams currently with sufficient command time on large aircraft) and then go and do contract work in the UK for 6 mths a year....or not as the case may be and the mood takes
Like everything else in this industry you can be glass half full or half empty
EDIT: Yes there are days when the last thing I want to do is go to work...like when the wake up call comes in Dubai or Bangkok in the middle of the night before an 8-12 hr sector, you really would rather stay in bed...but sliding into my seat in the 767 always puts a smile on my dial.