London at 4,640 dollars a month is 2.1x Lisbon at 2,180. London wins jobs and salary; Lisbon wins cost, climate, and the long lease math.
London wins for the 24 to 32 year old early career tech, finance, or media professional who needs the brand on the CV. Lisbon wins for everyone else. London median professional salary 104,000 USD PPP versus Lisbon's 48,000. London cost of living 4,640 a month versus Lisbon's 2,180. London wins on absolute income; Lisbon wins on the take home minus rent gap.
Rent 1BR Zone 2: London 2,320 GBP, Lisbon mid city 1,180 EUR. Groceries: London 480, Lisbon 340. Transport: London 162 (Zones 1 to 2), Lisbon 40. Eating out (2x week): London 380, Lisbon 220. Utilities: London 280, Lisbon 140. All in: London 4,640, Lisbon 2,180.
Safety: both 8.4. Weather: Lisbon 9.1, London 6.0 (rain, low light winters). Jobs: London 9.4, Lisbon 6.4. Tax: UK effective 42 percent on the 104,000 USD median; Portugal NHR at 20 percent flat for 10 years on foreign income.
For salaried tech, finance, media: London. For remote work plus quality of life: Lisbon. The highest paying ranking covers the salary view.