They do it on purpose with Siennas. It got much better, but still there is a wait time (like 6+ month) and you can find them at msrp. During Covid and just a year ago it was 1.5-2 year wait time and $20k+ markups and gimmicky add-ons were common. Used vans were more expensive than new, because you could get them right now. People say it is still hard to find lower/cheaper trims, but if you want to shell out 55K for on one in top trims ,they will gladly find you one…
Kia had same problems, but they did rapidly ramp up production when they got opportunity. As a result a lot of people looking for Sienna went Carnival route (it is a nice van, just lacks hybrid and less reliable).