Welcome to the Forum!
Why new??
Buying use provides:
Lower initial cost. Let somebody else pay that huge first year depreciation.
Virtually all new RV have some (some have many) factory OOPS that need fixed. Warranty covers this, but some dealers make this a very low priority, and the new camper sits on their lot for a month for a simple repair. Less experienced service techs sometimes break more things than they fix. Every trip means you tow it to the dealer, and make a second trip to pick it up. You can not go camping while the dealer has your camper. Buying used allows the original owner to get all of this fixed for you.
If you do not get the "right" camper the first time, the cost to trade for the one you really want is much less.
Lightly used campers are readily available. The original owner may have decided camping was NOT for them, or they bought the wrong camper. Poor health often forces some folks to give up camping.
Sometimes a gently used camper comes with upgraded sewer hoses, water hoses, or power monitors or a myriad other nice accessories.
Just some things to think about!