The teams have secondary channels they can switch to. They switched when someone interfered with the radios of Alex Bowman and Kyle Busch during a race a few years ago.
Maybe they should follow Formula 1 and switch to TETRA 🤔
The teams have DMR capabilities as most, if not all teams use Motorola XPR radios. NASCAR officials already use encrypted DMR. The fact that race-related comms are still analog is for the fans. Racing Electronics scanners are very popular with fans and even the media. They are only capable of analog, as are the old Uniden NASCAR scanners from the 90s, which many fans still use. They don't HAVE to use analog, but they do anyway because they know fans like to listen. To say they still use analog because they're out of touch just isn't true. In fact, a brand new Cup Series car was used beginning in 2022. It's a completely new and advanced design that has been years in the making. NASCAR is anything but behind the times.
Here's a case study from Motorola about NASCAR's radios: