If you’re trying to sell something, you need to be where the customers are. If they’re on Marketplace, that’s where you go. You can easily list in both places.
Marketplace is literally the only reason I still have a facebook account. Unfortunately the alternatives here get nowhere near the same number of buyers.
I think a good chunk of people would be worried to buy/sell from/to an account with little to no activity at all. This is very strong signal of low effort spam already common on FB Marketplace.