Ordnance Survey maps are fairly well done (as good as other sovereign efforts), but the UK's approach to map licensing has probably hurt the country economically and heavily limited distribution of OS maps. OS is maybe the most antiquated map licensing agency I've ever tried to work with.

In the US, you can get the USGS maps for free. In Switzerland or France, you can get SwissTopo or France IGN in a manageable way for reasonable licensing fees. In Australia, it's a little complex, but you can go province by province and license the maps, sometimes for free. Many, many countries provide high quality maps for free or reasonable fees.

But Ordnance Survey's maps are incredibly expensive to license, hard to administer/govern, and can't be purchased for much less (if less at all) than OS charges in their own (terrible) app. And thus aren't in my app like so many others are.

The US approach to making USGS maps public domain has created enormous economic growth. This is a nice paper on the economics of maps: https://pubs.aeaweb.org/doi/pdfplus/10.1257/jep.34.1.196