By the way, I think IT and electronics are still developing in a qualitative way and will continue to do so, if you look beyond the consumer items you mentioned.
Recession stage of the wave doesn't requires complete advancement halting. Problems in economy start to appear when the speed of development falls under some threshold. Automobiles are good example - there are still some advancements (e.g. hybrid and electric vehicles), but in general auto industry and car sales are falling no matter from it.
Bitcoin is an example of this.
Kondratiev theory state that in the recession stage capital turns into speculative instruments, therefore you may feel bullish on BTC/USD price
(at least until 6th wave will not start).