If bitcoins had constant or decreasing value through time then people would be more willing to trade them. This is why deflation is so economically dangerous.
It did encourage mining, but that doesn’t driving long term adoption and has nearly purely negative consequences.
The ideal long term strategy for adoption would have mining to provide a consistent reward in real terms over a long timeframe, low costs and high transaction volumes, and for unused accounts to be charged a small fee. Bitcoin failed all of those which is why it’s never had significant adoption as a currency.