My dog was crate trained as a puppy because I wanted to know she was safe when I had to leave her, although it was only for short periods and overnight.
However, I soon realised that she wasn't going to chew anything and harm herself so I started to leave her loose in the house and she gave up her crate when she was about six months old.
I wouldn't leave a dog in a crate while I went out for the day it isn't fair and with most adult dogs, it's completely unnecessarily.
You're not over thinking this OP and it's a very responsible way of looking at potential dog ownership.
A dog does change your life enormously and will seriously impact on your freedom.
Having said that a well trained well behaved adult dog is a joy and should be able to go to the beach, and many other places, with you without any trouble.
But, you won't be able to go out for the day or away for the weekend on a whim unless you have someone willing to take your dog at short notice, or you go somewhere dog friendly.
Holidays will be more expensive because you have to factor in the cost of care for the dog, unless you have family will to take him/her for a couple of weeks, or again you go somewhere dog friendly.
In addition there are vet fees to pay, insurance, feeding.
Dogs are a big responsibility, they need a lot of input and training if you get a puppy and some older rescues can, but not always, come with issues.
It very much depends on how much you want a dog and how much freedom you're willing to forego.
A lot of rescues won't rehome to families with young children so you might find you have to do a lot of research to find one that does.