So, nearly any "online" sale is cannibalizing the dealer's investments.
I suspect that Tesla would actually prefer to sell cars at dealers (that are owned and operated by Tesla); their online sales are just a hack to get around the fact that their dealerships are banned. So any concern about conflict of interest between the dealer and manufacturer seems like it does not apply to Tesla.
Intel has a habit of putting out PR that mixes stuff that is available now, stuff that will be shipping this year, and stuff that may or may not be shipping five years from now. The press loves it but it's annoying and confusing to us technical people. (Whatever you do, do not pay any attention to "rack scale architecture".)
When it comes to silicon photonics specifically, Intel has been talking about it for years and still hasn't shipped anything.
Making silicon photonics cheaper than VCSELs must be really hard because it seems like nobody is shipping them. Or maybe silicon photonics are only cost-effective for parallel fiber optics which are a pretty small fraction of the market.
A lot of transactions can be pruned out of the Bitcoin blockchain (this isn't actually done today, but it is possible), so other blockchain-based systems would be wise to design their data formats to allow efficient pruning.