Supply chain performance and effective e-fulfilment channels lie at the heart of this. There are many third party service providers who will provide competitive solutions that help to level the playing field. A carefully designed distribution strategy sitting alongside responsive customer service programmes are critically important. Retailers must be equipped for an Omni-channel world where the consumer is often agnostic to a physical retail experience. Post sale costs such as returns management need to be stringently managed within the Omni-channel model.

We shouldn't overthink the origins of the death spiral in retail. The degradation in retail has been going on for a longtime; beginning in the 1980's. It is primarily a function of demographics; the largest generation in history, the Baby Boomers. The Baby Boomers are spending less and less as they age; in particular today they are not spending on apparel, home goods, home improvement, etc. but they are spending on their heathcare and leisure activities. Amazon and eCommerce is siphoning off sales from a smaller pie that is already overstored with the tradtional bricks & mortar department & specialty stores.
Pursuing an omni-channel retail strategy in itself will not be enough to stop the death spiral in retail. Improvements in the efficiency of the retail supply chain, infrastructure, and marketing strategies with new technologies and methods such as: a real-time virtual ERP to better control all software systems within the retail supply chain; or advanced AI analytics to process and use big data inputs; or AR/VR to improve the shpping experience will help retailers of all kinds to better compete. Multi-use or cross purpose destination retail locations for a total and memorable consumer shopping experince will help attract (foot traffic) shoppers of all generations.
However, there are too few retail shopping dollars chasing the vast number of retail stores in existance today. This don't account for the emerging new retail concepts constantly being built-out or the unlimited competition with the low barriers to entry that selling on the Internet allows. The process of reducing the number of retail doors in combination with the revolution for how retailing is going to be done in the future will be a very painful process (losers and winners) and will take more time (years) before an equilibrium is reached; adapt or die!