For taxiing they use GPS just as Google Maps for driving, but it is mostly for pilot convenience to look at a screen and taxi than to look outside at the taxiway markings which in some poor visibility conditions are hard to spot and without the GPS they would I guess require a Follow Me car.
Regarding the runway incursion scenarios, you need to pay attention to the lights on the taxiways, because runway entries are highly illuminated and visible even in really low visibility conditions. You just don't enter an active runway by mistake.
"Paper charts" as you call them, are physical charts of airpots maps akin to a city map. And as a pilot you are required to know how to read and use those maps. Just as with SID/STAR charts. Pilots are expected to know how to fly using only basic instruments (airspeed, altitude, attitude, vertical speed, compass, banking), and even with some of those not operational.
Long story short, GPS jamming at an airport is an inconvenience rather than something critical.
Regarding the runway incursion scenarios, you need to pay attention to the lights on the taxiways, because runway entries are highly illuminated and visible even in really low visibility conditions. You just don't enter an active runway by mistake.
"Paper charts" as you call them, are physical charts of airpots maps akin to a city map. And as a pilot you are required to know how to read and use those maps. Just as with SID/STAR charts. Pilots are expected to know how to fly using only basic instruments (airspeed, altitude, attitude, vertical speed, compass, banking), and even with some of those not operational.
Long story short, GPS jamming at an airport is an inconvenience rather than something critical.