I wouldn’t be overly concerned. True, GPS units are very sensitive radio receivers and as such, subject to jamming and electronic countermeasures. However there are features of GPS (implemented in safety critical units such as those used in aircraft but not the low-cost consumer ones - yet) that can further improve reliability. RAIM Receiver Autonomous Integrity Monitoring - is one example.
“However there are features of GPS (implemented in safety critical units such as those used in aircraft but not the low-cost consumer ones - yet)”
How many in the general public are willing to pay over $2,000 for a simple unit in their car.
Personally I don’t mind the expense of aircraft units because I value an equal number of takeoffs and landings!