> the guy in first place has to spend all that time and effort to develop the thing

The problem is that patenting something doesn't require one to put a lot of time and effort - just to produce few pages of text and diagrams. So it might be sufficient for somebody to have a general idea.

Then 25 years is too much.

The problem often stems from the Patent Offices getting caught flat-footed with new tech. When the patent officers don't know enough about the field they are reviewing it is easy for things which are "obvious to experts in the field" or "overly broad" to slip thru and cause major headaches for everyone.

> It is an attempt to solve the real problem that it is much harder to be first than second

Sometimes it is significantly harder. Often it's just a matter of luck

> But The basic idea is sound. If you invent a novel mechanism and publish it the government will grant you exclusive economic exploitation rights to that mechanism for the next 25 years. After that it is now fair game.

No. it is no way shape and form, good. 25 years is eternity in tech. The impact of the tech is not all that much related to investment either. You are just stifling any competition in the market

> It is an attempt to solve the real problem that it is much harder to be first than second, the guy in first place has to spend all that time and effort to develop the thing, and the guy in second just has to copy the guy in first. To rectify this social injustice the patent system was developed, where the government would grant and enforce economic exploitation rights of the mechanism to the inventor.

It has completely wrong structure for that. First, the duration. Second, the way you can patent vague idea, not actual concrete implementation. It is not used to stop competition from just copying your product, it is stopping anyone in market to compete.