I realize some info is not allowed to be posted, but you are not really saying what resort and season you are trying to rent so it's hard to say how desirable your reservation is.
If you were on the opposite side of the transaction, and had a minimum level of savviness, where would you go to look?
- Vacation Candy where every listing is marked up by $500, which is a 20% markup on a $2500 listing.
- Koala where the owner is charged 8% (and likely marks up their price to compensate), and the renter is charged 10%, so you're often paying a 15-20% markup.
- Redweek, where you can rent at the price the owner listed if you don't use verified and protected (or pay an extra 10% for the "protected" service if you so desire).
IMO, the first two have a non-sustainable business model. For example, Go Koala will charge you $300 for a successful rental, but if you mark up your unit because of that you make it less likely to rent. Sure, Redweek charges ~$40 on every 6-month listing - and maybe you have to pay it twice before it rents - but if you price it attractively enough (relative to other listings), it's more likely to rent than not.
That said, yes it is harder to rent. Some of it IMO is due to covid because many people changed their booking habits and no longer reserve 10+ months in advance. It's also due to increased supply with many owners looking to rent their timeshares to offset rapidly rising fees.