> Insider trading is one of those crimes where it is a bit ambiguous as to what the crime is (at least to me).

That is because you appear to have a false understanding of what insider trading is.

> Information travels with some speed and there will always be people with access to better information making better decisions.

That is not a problem at all, as long as the information on question is not sourced from deliberately undisclosed sources within the company itself or within their business partners.

Encouraging investing time and money into interpretation of publicly available data as best as possible to gather information about a company's future prospects is a good thing, because it helps one of the main purposes of public stock markets, which is slapping an as-accurate-as-possible price tag on a company, so investment capital is put to work as efficient as possible. And since it is solely based on public data, this obviously does no undeserved harm to the company's business prospects.

Conversely, encouraging using information that is still kept secret to do this thwarts the future prospects of the company in question, because that information is usually kept secret for business purposes, and if it wasn't secret, deals would not take place. Hence by encouraging using that secret information to take part in price discovery it is effectively encouraged to break confidentiality of that secret information, which is contrary to the interests of the company wanting to make business in the first place.

> We have much better technology these days.

Technology does not have anything to do with this fundamental discussion

> Rather than making trading some sort of crime we should just have a "relevant persons" standard where CEOs and anyone who has close contact with them have to register what they are about to do a few days before they make any trades of shares in the company.

Your argument is self-defeating. Because in order to make officials adhere to the "inform public about intended trades X days before they take place" rule, you MUST make these trades illegal if they happen without this pre-announcement.

Such rules are indeed in place right now, precisely to combat insider trading. This is why people with inside knowledge often try to pass on that knowledge to friends or relatives instead of trading for themselves, which is still illegal insider trading, but much harder to prove.

> It is fundamentally a bit silly have a situation where it is illegal for someone to make best decision given their knowledge.

No, it is not, in case of insider trading. It is fundamentally a bit silly to expect people to participate in a market that does nothing against insider trading, because if you have to assume that regardless of how good your research based on public data is, your counterparty on the market is likely someone with direct access to confidential insider information and will thus make the better trade, any possible trade must be assumed to be a losing trade, hence participation in that market would be a bit silly in the first place, which eventually kills the entire public market because it just leaves those with insider information actually trading.

If you want public markets, you need to limit trades to be only based on public data, otherwise the public will not have any confidence in the fairness of the market and will decide to stay out of it.

> We can safely guess that the professional traders are leveraging every possible edge, fair or not, SEC regulation or not if they think they can get away with it.

Again, you are misunderstanding what is insider trading. Professional traders usually aren't, because trying to leverage any available public data to gain an edge (like the often mentioned satellite imagery that can be bought on the open market by anyone in order to count cars in parking lots of stores or whatever) is not illegal and totally fine within the purpose of the public market as described above. Insider trading originates from people in the company either directly using secret information to trade for themselves or giving trading tips based on that information to outsiders. These could of course be professional traders by accident, but often they're just retail traders, and in the end the nature of those traders is irrelevant for the discussion anyway, because it is about the nature of the trades and how they were informed, not who the traders are.