2021 was the year of Tandem market collapse around here.
I watched MANY sit on the market for months, some at very reasonable prices.
Spring of '22, I bought two that I recognized from two different "clean out guys" - they had been abandoned.
Santana Arriva and Burley Duet
Both needed cables, tires and tuning.
Fixed them up, managed to sell the Duet, and came out with a "free" Arriva and a profit.
Recumbent market went away about the same time.
Wasn't really until the end of '24 that the entire bike market collapsed.