As with many technologies, the internet is prone to getting a bit too far out over its skies. The adage is that one can find and buy anything on the internet and research every subject upon it. Somewhere along the way, that didn't quite pan out, and while it remains true to some extent, it requires far more effort than one can imagine, or is often willing to expend, to make it so.
Using amazon as an example, one can find almost anything on it, if willing to abandon amazon's own lame search function for any internet search engine, but one had best be advised to know what is being looked for exactly and not expect to learn even the basic details of it from amazon, which supplements a paucity of such information with user reviews it has combined over a variety of products from the same manufacturer. After finding that you cannot determine the product dimensions, rather only the size of the package the manufacturer ships it in, you can spend an hour reading reviews which presume you're buying one model over another, as if the models were the same. Both of these things are just laziness on amazon's part, and the kind of thing you'd almost never find on e-Bay, where sellers pay a penalty, in returned sales, for a product they did not fully or accurately describe.
Ah, but you're going to research the product on the internet, and thus know what you're buying, right? What you'll find there is that the review process has been co-opted by people who know little to nothing about the products, and merely recited the features of the top-ten best-selling products they determine via, again, amazon. You're lucky if you don't find outright false information. There are exceptions, with the NYT's Wirecutter doing a passable job but, as with Consumer's Reports, in many cases they're only as good as is a snapshot of product development. A year old review is of no use to a washing machine no longer made, and washing machine models change every two years now. That machine found most reliable hasn't been made in five years, and the only way it is known to be most reliable is because of someone reviewing it after five years of ownership. Your highly rated appliance may only signify its lights come on when plugged in.
So, where do you find all that information necessary to satisfactorily purchase a product? You find it within experts, also known as salesmen. Everyone within a retail line, be it sales or service, is a salesman, by the way. My insurance agency, which is about to become my former insurance agency, is transitioning to that status of former because they've employees now, under the influence of ownership, who do not recognize that they're salesmen, not mere claims adjusters. (They assert they hate sales, preferring claims adjusting, without a trace of irony in their voices, not realizing that when the customer has to do all the work in handling a claim, they're losing a future policy sale.)
The salesman's job, whether in actual sales or a technician in the shop or field, is to explain to you what you need to fulfill your wants. You need a pressure tank to replace the old one on your water well system, but you don't need just any pressure tank if your goal is reliability or to have better water pressure to the remote regions of your house. Where are you going to find that information?
If you buy your car online, who do you complain to when it proves unsatisfactory or the service department cannot seem to fix it? If you bought it through a salesman, at the first hitch in the service process, you go look up that salesman, who hopes to someday sell you another car, and get him or her on the case. They know where their bread is buttered if they're any good at their job, and their job is primarily referral based. Go in to see Wally, he'll take care of you, is how most of their sales take place. It's either that or you better learn a lot about cars before you buy, which you can do, but can you do this for everything you buy, often spending a lot of money in doing so? If you have a great auto mechanic you've used for years with great satisfaction, he's the first person you ought talk to about your next car purchase. though he nor you may not view the conversation as him taking on the role of salesperson. After all, he's only an expert on auto mechanics, and doesn't make a living publishing glowing reviews of the next beautiful shiny object on wheels. Find your auto mechanic, then buy your car, is not far-fetched advice.
There aren't many salesmen left, because the public has perceived them no longer necessary, and their employers have followed that lead, eliminating their positions. They're eliminating an expense, while they're also eliminating possibly decades of experience. The end result of that is appliance stores, for instance, become volume sellers with whatever sales people they have of no experience. You don't know the right questions to ask and neither do they.
When you find a good salesman, the number one thing he or she is going to do, aside from selling you a product, is assure you his company will be there to back up the product, first by selling you the right product for your needs, and then by assuring you they can maintain it for you, and won't blow you off when problems occur.
The primary advantage you as a consumer have with a salesman is that sales person sees a direct connection between their paycheck and your satisfaction. Why would you surrender that?