This exactly. Less relevant for people from the U.K. but huge networks of communities of all countries, lots more choice in restaurants, shops and attractions and easier direct access home from Heathrow or the other airports. Day trip from St Pancras to Paris in two hours in luxury, similar to travelling from Newcastle to Manchester on the manky Trans-Pennine rattler.
Newcastle is a great city but London is a mega city and, despite its many downsides, has loads of upsides too.