This is going to be way cheaper than buying a Stream Deck, but it will certainly cost a bit of time and effort getting it together.
What it will do is allow for up to 8 different paper templates to be inserted with custom button logos (think of these templates as Stream Deck pages). The colour of each button can be changed, as well as switching between a press function or a toggle function. The button presses basically function as controller button presses or toggles.
What it is not going to do, though, is display any information back from the computer onto each button, or indicate any status back through a button, which a Stream Deck can do.
Besides that, though, it is great for having custom buttons set up for games to control lights, gears, AWD, horns, camera views, etc.
The video in the linked article does a good job of showing how it works.
See https://hackaday.com/2024/08/13/cheap-diy-button-pad-uses-neat-punchcard-trick/