Nor will the oldies spend a lot on clothing and footwear. This is interesting stuff for you and me, but vitally important for the planning of retailers and manufacturers. If they can't make smaller cars locally, they'll lose market share. Other manufacturers will need to change the proportions of many products - from the cut of jeans to the weight of gardening tools. Shopping malls will have fewer sports stores and music outlets, but more bookshops.
Mature customers are likely to be more comfortable being served by mature-age workers.
Airlines and travel agents will have to pitch to different market demographics, with fewer backpackers and more travellers willing to pay a little extra for comfort. The housing industry will need to build fewer and smaller new homes, but with higher quality fittings and greater emphasis on safety and security. Not all change is pernicious and not all of it is instigated by economic rationalists and the dark forces of globalisation. Some of it is no more than what the customers demand.