Ten companies from five European countries have demonstrated a sense and avoid system for large drones they intend to certify in the next few years. The European Detect and Avoid System (EUDAAS) was installed on a Leonardo Falco Xplorer drone and demonstrated at Trapani Birgi Airport and did well enough to advance to the next phase of testing.
The first thing we need are these things blasting out ADS-B and lights and strobes and make them as anti-stealth as possible and paint them bright colors. Make them as outrageously visible to eyes and tracking and radar as possible. Heck, glue some mirrors on these things for good measure.
Don’t make them (like in the picture) grey and stealthy and unlit. See/sense and avoid works both ways or not at all.