I only learned the concept recently, here as a matter of fact.
1) We all know that higher voltage has two benefits, smaller conductors and lower losses. BUT---
2) Since the inverters can digest a wide variety of voltages, within their design tolerances, you can accept a voltage drop in the DC solar feeds that would never be acceptable in a fixed 240v, 60hz AC environment.
3) Thus it comes to trade offs -- you could have perhaps a 10% loss over several hundred feet, say 500v to 450v, but as long as it stays cool and you are OK with more panels to handle the losses, its OK. (Just seat of the pants reasoning there)