There was a time when cutting the cord meant cutting a cord. Ie: in 1985, when you got tired of paying for cable TV, you would disconnect/cancel/cut the cord. Your $30 bill went to zero and you watched whatever your antenna could pick up for free. The old cable cord was no longer in use, and could indeed be cut out if you liked.
Recently, some people say “cut the cord”, when they haven’t cut any cord at all. Often, they have just stopped paying their cable company to supply content and simply pay someone else for content delivered on the same cord. (This variation on “cut the cord” seems rather silly to me but people say it all the time.)
It’s not to surprising that if you use the second version, and you insist on exactly the same channels as you had before, then the price should be quite similar. Ie: same content, delivered on the same un-cut cord. Content still has to be paid for. Cord still needs to be installed and maintained. Makes sense that it would cost about the same.
But if you can be more flexible, then you can make streaming pretty much as cheap as you want.
Or, if the TV is your only form of entertainment anyway, you could go the opposite way, and use Roku to ADD additional content!
There are lots of ways to go with streaming. It’s not one size fits all.