I've lived in Adelaide, Melbourne, Sydney and Perth.
Adelaide has by far the best beaches - hitup Henley Beach just 15 minutes from the city, extending west beach, sea cliff etc.
Port Noarlunga, Port Elliot are also fan favourites.
Paul, I don’t know how long ago you lived in Adelaide but the last 3-4 years has seen a surge of small restaurants and bars in lane ways that are excellent: bread and bone or peel st for food, Bank st social/clever little tailor etc bars near by.
One of the few cities which have about 10 brilliant small bars right next to each other.
The coffee is similar standard to Melbourne: places like Flinders st project, Tell Henry etc
In comparison to Perth in particular, I’d say Adelaide is similar but a fair bit busier than Perth, I always found the city in Perth to be virtually empty.
Being cheaper, with nice weather, good restaurants bars coffee, great beaches 15mins away and nice hills towns 20mins away, the downside has always been the shitty public transport and lack of private entity jobs that forces young professionals to leave for greener pastures