So under your logic, if phones have gotten cheaper as they have advanced, then why have bikes gone the other way as they have advanced?
Because mobile phones went from being a luxury item used by only the very wealthy to being a ubiquitous daily life accessory, and an access point for many other cash sources. In many poor countries, people who have nothing more advanced than wooden implements have cell phones, because the cell phones support the banking industry. Nobody needs a cash economy if you have cell phones and banking apps, and the banks, which had no place in those nations' economies for most of the populations, are now raking in the bucks. People who mostly barter and deal only in small sums of cash don't use banks, but as more people got phones 9to be connected to each other) they also transformed the economy from barter and cash to credit transactions---stores do sales via pay-by-phone, workers are paid via direct-deposit pay-by -phone, bills are paid by phone ... suddenly the banking industry had its finders in Everybody's lives, not just the wealthy and upper middle class. Complete transformation driven by cheap cellphones.
Bikes (at least in most of the "Western World" or "First World" ... have goner exactly the other way. Bikes are rarely used for transport, and those which are are usually the cheapest bikes and are used by the poorest people. Bikes have gone form transport/toys to "serious sports equipment" and for the upper end of the price range, right into "luxury hobby" status, like power boats and golf clubs---you can buy the utilitarian bass boat or driver, but the good stuff is very expensive.
Seems pretty simple ... not sure why people cannot fathom this. Luxury goods are priced on social cachet, utilitarian goods are priced more for volume sales.