Stores like Walmart have changed a lot of industries, including the vacuum cleaner industry. Most consumers walk into Walmart and they'll see the $39 Bissells on endcaps, a long line of Sharks ranging anywhere from $99-$250, a few additional Bissell models, a couple of Hoovers and Dirt Devils, and maybe two Dyson models. The locations near me sell a single bagged model, the bagged version of the Powerforce. I haven't seen any canister machines in a Walmart in a long time.
When most consumers see this, they either pick the $39 Bissell or they'll buy the "high end" Shark for $200. These people can't fathom spending over $300 on an actual higher end vacuum cleaner, because stores like Walmart and companies like Bissell and Shark have convinced them to buy a cheap vacuum to use for a couple of years and replace. This is helped by long warranty periods that are convoluted to actually take advantage of, oftentimes it ends up being easier for the consumer to buy a new machine than it is to pay to ship the original back to the maker for repair or replacement. Someone in an earlier reply claimed that the market share is 50/50 for bagged/bagless machines. I can't see how that could be true. I recently explained the concept of a bagged vacuum cleaner to someone because they had almost zero understanding of the idea. They asked me if it gets tiring having to wash out the bag every time I vacuum. We have many people who have either forgotten about or have never known about the existence of bagged vacuum cleaners. We are at the point where people who were raised with Eureka Whirlwinds and Fantoms are starting to move out of their parents' houses to furnish their own residence, and most of them are going to understandably buy the cheapest of the cheap for everything. From bed sheets to vacuum cleaners, many of them are buying the cheapest items they can find at Walmart. This is a deeper problem with how wasteful our society is, companies have trained us to buy low quality goods and replace them more often. This provides a steadier stream of income for the producers of consumer goods.
At this point, bagged vacuum cleaners on the American market are almost exclusively at/near the top end of the market. There are very few machines under $200 that are bagged relative to the number of bagless machines in this same price range. I agree with what Kenny Loveland said in an earlier post, high end portable vacuums are slowly being phased out in favor of alternatives. Robots and cordless stick vacs are all the rage right now. I think we will be lucky to see central vacs gain in popularity, I hope that ends up being the case but I think it would be tough to see it happen. I have never known a non-collector who actually liked using their central vacuum system, many consumers find the long hose to be cumbersome. Hide-a-Hose systems are helping to remedy this, so we'll have to see what the future brings.