I’d say fix it up. It’s always nice to have a spare bike; and if you do a lot of different kinds of riding, you can fit the bikes out to be better for certain kinds of rides.
Here’s a few of mine; 1997 SoftRide for “sporty” road rides; the black ‘96 Cannondale is my dedicated trail MTB, and I just picked up that red-orange ‘88 Klein to build a “knock-around” city bike
One benefit to using “nice” older bikes is that you can build a stable of different bikes for about the cost of a single new bike.
