Peter wrote:

"Peter R." wrote

Since the free signal from the USA is plenty good enough for en-route
navigation of cars, boats, and planes, it is pretty obvious that any
attempt to raise money from planes would have to involve authorised
GPS approaches being conditional on the carriage of a prepaid decoder
for the "better" signal.

The US system is good enough to support RNP 0.10 instrument approach
procedures when combined with redundant FMSes, EGPWS, and Baro VNAV.
It's already being done by the Aussies and Canadians using the US system.