Your timeline is off a bit. I sold routers at my computer shop from Linksys. Hell, the WRT54G came out in 2003. That was already a 3 in one device.
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Yes, they existed, but I clearly remember they weren’t a common thing in 2002-2003. At least not in Latvia. Around 2005 I worked at small ISP in Riga (main reason for cheap and fast Internet here - lots of competition), then WiFi at home was already more popular. But real explosion happened with iPhones and later Androids.
Okay. Maybe in Latvia things moved a bit slower. I am only speaking from my experience in the USA and from my experience selling these devices.
In 2004, when I started dating my wife, we drove around my town with a laptop and a WiFi PCMCIA card and detected over 200 insecure WiFi networks. I used this as a marketing campaign to secure people's home networks. I don't remember how many secure networks I found back then though.