Simplified history of LED displays:

1970s: Dot matrix displays (low cost; relatively simple production; stable performance <> poor colours)

1990s: Dual In-line Packages (better colours; suited for outdoors <> low efficiency compared to newer technologies)

2015: Surface Mount Device (improved colours; smaller pixel pitches <> anti-static measures and outdoor protection complicated)

Future: Chip On Board (improved performance; lower carbon footprint <> still relatively expensive)