It's really not that bad

I subscribe to the theory that every rail should be soldered to something--either another rail or a feeder. Others say a feeder every 10' is good enough, while others report having gotten away with feeding an entire layout with one pair of feeders.

The game changes as soon as you paint the rails or glue ballast. The paint or glue works its way in between the rail and joiner, and turns an electrically conductive connection into an insulating one. This might not be a 100% insulating connection, but it often is enough to stop trains.

Now there's an insulating connection and the ballast has been laid or the rails painted. Fixing the connection requires either scraping some paint off the rails or drilling through ballast. The easiest repair is to drop a feeder at that point, so now there's a hole for the feeder and a bright shiny spot on the rails. Might as well do it before you start.

Compared to repairs and time that must be spent doing diagnosis, dropping a feeder to every rail is really not that bad.