Yeah. Except time and money. Or maybe the simulation would be too inaccurate and only give a false sense of safety? That's the only reason I can think of why not to do this.

That's all good in theory. However, the RAM on Voyager 1 is an analogue tape recorder, so it will eventually just stop working.

The computer(s) onboard is also the computer-system made by mankind that has been turned "on" for the longest time of any computer. It has never been turned off since the launch in 1977. There's no other computer on Earth that has managed to run consistently for anywhere that long, and frankly I'm unsure if we even could. Theoretically it should be easy, but in practice... I doubt it. Most traffic signs need calibration annually or more frequent.. This thing has been flying through space for 46 years and carrying out Fortran commands every day and now it just doesn't. If there's any physical problems... It's impossible to revive.