Imagine a scenario when all mobile phone companies finally decided to add a custom default bitcoin wallet to all of their devices as factory app. I believe that will further increase the adoption of bitcoin
Wack, all surveillance agencies would welcome this. Default bitcoin wallet on mobile threatens you privacy because of gyro sensor on board of cell phone. The data from that sensor can be easily lifted, so surveillance agencies use it to their advantage to build the fingerprint of your walking manner. If you care the privacy of your transactions don't keep bitcoin (and any crypto) on mobile.