I know a guy who makes his living flipping collector cars. He once told me that during Covid, the demand for project cars took off. People had time on their hands and money to play with. I was furloughed from the museum for a few months and during that time my Covid-spec unemployment was much more than I was making at my job. I spent most of my time working the family farm (cut brush along the entire western line), but I also had time to exercise on the vintage Nishiki 10-speed I bought new, and I played my guitars more. I had bought my Dart in 2019, it came out of the paint booth in July '20, and I worked on it some then too.
Another thing that flipper guy told me was that some cars sell quicker and for more than others. The hottest items were GM cars that any IT guy can drop an LS in, while the slowest sellers were the ones were modern swap options were limited or nonexistent.
Prior to Covid, there was a lot of talk in the music business about how few young people were learning to play actual musical instruments. Musicians were aging out and dying off, instrument sales were declining rapidly, instructors and luthiers were closing up shop, etc. Then in 2020, suddenly people had time and money to pursue interests they always wanted to try but never had the time. Instrument sales shot straight up and the prices followed. The used guitar market went nuts, with even plain, common models of recent production doubling and tripling in a couple of years. All of my guitars are worth much more now, but none are for sale. Now I'm hearing about prices softening again, but I usually build my own these days so I haven't seen a drop.
What the market is like these days probably depends on what you're buying/selling and where you live. I would have more cars if I lived at the farm, as there is more room for a big garage/shop, and the quiet roads in the countryside are better suited for cruising a classic than, say, driving in Nashville.