Multiple sources of credit, not just a bank, i.e.
Credit cards (I have several credit cards with different banks with combined credit limit close to £75k! though I always pay off in full every month. Could easily go on a wild spree if I wanted to!).
Car loans, leases, hire purchase - again, different lending firms, a couple may have 3 cars between them, and if they're new on lease/loan/HP, 3 cars easily can top £75k, or more if any are say a camper van, or a £50k Merc or a Tesla etc.
Easy to get unsecured bank loans for other things like a caravan or boat.
Easy to get unsecured finance for furniture, home improvements such as double glazing or new kitchen/bathroom.
Pretty easy to get up to £200k or so if you've been getting finance from the retailer/supplier of your cars, caravan, kitchen, sofas/beds/carpets, double glazing, etc etc.