My answer is similar to others, it depends. I have traded away vintage for modern and vice versa. My hesitancy to trade my vintage cards for recent cards is both a supply and demand issue as well as what I am looking for. My primary focus in collecting is Red Sox, all years, brands, etc, I want them all. My secondary focus is bulding vintage sets, which is a much lower priority for me.
The supply and demand comes into play, when, lets say you offer me a 2021 Topps Devers and JD Martinez, which I do not have yet and you want a pair of 1966 commons in exchange. Yes, I want the two 2021 cards, but they are so common and plentiful, that I can pick them up for 10-25 cents or will acquire them as part of a lot, but it is not the same for the 1966's.
Looking at just the supply and demand on this site for two current stars and two 1966 commons..
2021 Topps 20 - J.D. Martinez - there are 603 in collections, 15 on wantlists, and 138 available for trade
2021 Topps 226 - Rafael Devers - there are 596 in collections, 19 on wantlists, and 121 available for trade
1966 Topps 6 - Chuck Schilling - there are 183 in collections, 43 on wantlists, and 12 available for trade
1966 Topps 93 - Jim Lonborg - there are 184 in collections, 46 on wantlists, and 15 available for trade
Just looking at that there is less supply and more demand for the vintage, and far more supply on the modern.
Now, if I needed one card to complete a set, of course I would trade vintage for it, If anyone has a 2003 Topps Gold Tim Wakefield, or 2003 Splendid Splinters Ted Williams #19 available, I would glad give up vintage or a lopsided trade in your favor to complete either set.
Otherwise, if you were to offer me the above mentioned Devers and Martinez, yes, I want them, but not badly enough to trade the 66's. Sticking with 1966, I have 394 of the 609 cards in the set and would rather hang onto the doubles in hopes of trading for other commons from that set.
Anyway, that is my two cent on the subject, hope it helps.
Scott
Red Sox collector...current count 62,000+ different