Devices like the Garmin [0] were chunky though, weren't they, like a few cm thick, even compared to phones of the times they were big. And to my [limited and shaky] recollection people had car mounted antennae for GPS (in the late 90s) because they worked poorly without it?

The first retro-fittable GPS was in 1997, the Alpine CVA-1005 [1], which weighed >3kg and had a display of 26cm across; it connects for nav to a CDROM drive containing base unit [2]; here's the wiring diagram [3].

[0] https://spectrum.ieee.org/consumer-electronics/gadgets/the-c... [1] https://ndrive.com/brief-history-gps-car-navigation/ a good review of early GPS [2] https://www.ebay.co.uk/itm/Alpine-NVA-N751A-Navigation-Syste... [3] https://elektrotanya.com/alpine_cva-1005_wiring_diagram.pdf/...

Chunky doesn't matter for a car GPS. They sit on your dash, not in your pocket. For my old garmens, the weighted sandbag mount they used to hold the device onto the dash was honestly less frustrating than a suction cup that falls of the windshield down to your feet while you a driving on the highway.

Oh, for sure, but surfsvammel was on about tech that fits in your pocket, you responded that GPS was 90s tech, and I was just fleshing out that whilst it was 90s tech it was only really widely available as tech for a car (and of course USA restricted GPS accuracy, which meant it often got confused in the UK as to which road one was on).

The last Garmin my dad had, maybe 5 years ago was decidedly chunky compared with phones at the time (but you need a reasonable sized screen and the use case meant it didn't need to be thinner, so perhaps not a fair comparison).

GPS nav hasn't improved much since the 90s, but smartphone nav relying on multiple positioning methods has improved remarkably in even the past 5-6 years. It used to be neither a dedicated GPS device nor a smartphone could handle dense urban areas (where buildings cause satellite interference) if you were moving much faster than a pedestrian.

True, but also your phone utilizes the same GPS signals. It's all about the maps. Your Garmin typically had maps for the whole country preloaded, your phone typically downloads them on the fly. So in the boonies your phone knows exactly where it is in terms of longitude and latitude, but hasn't a clue where anything else is.

It's not just about maps. Unlike a dedicated GPS device, your phone uses A-GPS for faster geolocation. Before A-GPS, you often need to wait a couple minutes before the device has any idea of its location or the time. Offline maps are available for both phones and non-phones, and aren't an issue at all.