Not surprising
Market is mature and saturated - same as PCs and laptops. It is only like for like replacement now and the reasons to replace are no longer pressing.
I have a stack of 2 semi-retired, 1 in minimal use and 2 in use in the household. The ones in use are one year old models and they still run everything fine. They are a staggering improvement on the 2 year old ones which predated them by only a year. However if you compare that to the current crop the incremental improvement is no longer staggering - it is marginal. The product has matured.
It will take 2-3 more years for the ones in use today until the batteries, charger plugs or something else gives up the ghost. Then I will consider replacement. Before that? Why should I?