BTC is designed to be highly limited in supply and thus all prices denominated in BTC should drop over time by design of the currency. Everything else in society, if it was all on BTC, would do similarly. Basically your salary this year should be smaller than it was last year but your buying power should be similar.

This encourages people to hold BTC because its relative value increases over time. Thus BTC by being deflationary encourages holding and not spending. It will lead to a less dynamic economy than if we had an inflationary currency which encouraged spending/investment.