My vote is to keep the Civic. However, I will say that if you’re looking for that Magical Unicorn car that does not have recalls, service bulletins, or chronic to some degree problems; there ain’t no such thing.
Note that the CIvic has a number of Recalls out on it and if none of them have been performed then it would be adviseable to have all applicable ones done. It’s free of charge so take advantage of it.
It’s not worth much right now. Because it has only 50k miles, it’s maximum value is in you keeping it. You have the best of both worlds. The lowest value older car for excise tax and insurance purpose and low mileage for reliable transportation. I have been in that position with older reliable compacts with great gas mileage, reliability and ultra low cost because of age. It’s car freedom at it’s best. No worry about dents or repair bills. Learn to enjoy. If you are not into financing, you have the perfect situation to start saving. An older reliable car you own outright should set you up well for saving for your next one. Life is good.