I don't think the local ski shop or local bike shop will ever disappear, and I don't pay much heed to such doomsaying. It seems to me that such predictions are often posited by those who would benefit from their occurrence, as a way to influence the reader and change their thinking and behavior.
But there are things a local shop can offer that no online retailer can ever match. Ski shop: boot fitting; helmet fitting; tuning and repair services; etc. Bike shop: bike fitting; demo rides (walk-in, chat about bikes, take a few for a spin to see how they feel); tuneup and repair services; parts and accessories (most shops around here offer these at prices similar to online, so why buy online?). The only time I buy bike parts online is when I need something unusual or unique that I can't find locally -- a particular tire, for example. But I would never buy a complete bike online. Skis are different, and I am comfortable buying online, and have done so several times. But again, that is often because I can't find a particular model here locally. And only after exhaustive study of every online review I could find, to make sure the model was appropriate and a good match.
Re. service, I do most of the work on our bikes and skis myself, but I would sorely miss not having a good local shop nearby to get some skis base ground, or a headset installed in one of our bikes, etc. That is the kind of work I have neither the ability, the tools, or the desire to undertake. And I find the cost of having a shop do it is very reasonable -- $45 for a stone grind; $20 to install a headset; $20 to true and tension a wheel...all bargains as far as I'm concerned. And while I'm in the shop, I often buy parts and accessories because it's convenient and the prices are quite reasonable (I likely wouldn't do it if I felt I was being gouged).