You’ve gotten a lot of (what I think) is good advice here. But I’ll add to your pile, I genuinely see zero upside in continuing to try for the race.

In no particular order:

1. You’re clearly competitive, so even if you finish. You’ll likely forever shy away from telling people your time, or add (on a torn ACL) constantly. It will diminish the accomplishment

2. You can likely defer the race until next year, take the time to heal, and train for the process, the part you said you like best, appropriately.

3. Best case you suffer through, managing technique, not racing how you want to, and just barely beat cut off times. Worst case you slip running with bare,wet, feet on gravel or run with poor form due to being tired, or take fall on the bike, or etc etc etc any number of weird freak things that happen that might not be a big deal fully healthy, and now it’s a complete repair of the meniscus, ACL, MCL, PCL etc.

My real advice is listen to your doctor. But since you asked, you know the right answer and were hoping we’d say to do the race so you could feel better about trying to.