To get a patent you must provide the full details of the invention, then your competitors can look at that patent and develop new systems that might be superior. This even applies to "software patents" (the different compression systems to beat LZ, or new versions of arithmetic coding - the most commonly derided "software patents" often seem to process/business patents rather than actual software).

This is the idea at least. In the absence of patent protection you get other problems: say you spent a year of your life coming up with a thing to do X, if you ship it some company can turn around and copy it without having to have invested any effort or money in the development, so can then also undercut you. "trade secrets" (an actual legal concept) doesn't protect you unless they steal the details from your company, but simply buying a product and reverse engineering (including decompiling) it is fine.

The problem is that the patent office allows patents that don't describe how to make the thing. That's where you get the BS style "X but on a computer", "X but with the internet", "X but with AI", ... or "compress data using some mechanism".

The patent office should just be requiring exact and explicit details in a patent application, so that you can read the patent and implement it. If you can't do that, the patent shouldn't be granted. (People periodically suggest "require an example implementation", but that for many fields there are huge costs involved in actually constructing a device so suddenly only people with a tonne of money can get patent protection)