If you don't run your own node:
  • you are trusting someone else with enforcing the consensus rules that define Bitcoin itself
  • you are trusting someone else with all your transaction data
  • you are not really part of the bitcoin network
Simple as that: run a node.
People buy and run routers and other always-on IoT devices with UI friendly configuration pages accessible on their LAN. It's just a matter of time (and a business opportunity) until the same happens with bitcoin nodes.