It's all about location. If you live in a strong market, great. In soft markets, not so hot.
Meanwhile, vintage parts are doing as well or better than ever. Sadly, some of the nicer stuff, a part out can yield 2X, 3X or even more than selling the bike complete. It's a shame. I have sold several bikes complete recently, at a discount. And I have parted out several as well. Part outs where the bike is incomplete, or has serious damage, are easier decisions.
And some of the 1980s MTB parts cross into the vintage BMX market that is still hot. Some road stuff also crosses into BMX. I had a 600 arabesque double crankset recently. As a road double, it was worth X. With just a single ring with single ring bolts, it was worth 2X. So I went the 2X route.
You do risk discounting a complete bike, only to have the buyer turn around and part it out.