These are all good points! Would love to learn your setup. I don't have much experience at all with camping. This is a major purchase for me and the goal is to go on long road trips and camp by lakes/rivers. Ideally I want to always sleep in the car just for comfort.
I have considered though not using the tailgate tent and get something like this just to hang out by a river/lake:
https://www.amazon.com/dp/B07GQGXWWW/
An alternative I'm also considering is something like this that doesn't require to be attached to the car itself and can be standalone: