Most major trains have an option to check a bicycle for $20, unboxed. If you have to use a bus the option won't appear. I've done it like 7 times now. Supposedly thru way buses will let you put an unboxed bike in the luggage cargo if it's not full (probably never full during pandemic). But I've only done that once. Usually if it's bought a couple weeks in advance cross country tickets are only 80-100 dollars. If you don't pay for the roll on bike service, they'll ask you to box the bike and pay the same amount for the box.
I used to hop with a foldable bike but it was too much i try to carry 90 maxI've never hopped freight with my bicycle as I tend to ride fully loaded and 80-100lbs sounds like a disaster on anything but a stopped train. Stealth camping is a lot easier because you can simply ride out of town to a forested and less populated area. I just learned how to use Amtrak cheaply in advance and making plans around it. It's never much more than $80-100 to get across the country with the bike/ gear safe. I also think since all the stuff I own is strapped to it, the lesser risk probably pays off in not having damages or having to replace bent wheels.
If you don't feel comfortable hopping freight with a bicycle, I suggest picking up a good busking/ spange routine and learning the Amtrak routes.