Dominic, I assume that since the post above wasn't flagged as political, I could give my perspective. In no way do I wish to get into the politics of why this is occurring - just the science behind the risk and each populations' risk tolerance.
On a high level this appears to be more of a tolerance of risk difference between the states such as CA and states such as FL, TX and AZ.
From an "immunity" perspective, AZ is now likely in better shape than CA as a higher percentage of their population has some level of immunity due to already having the virus. They are trending down now and I wouldn't be surprised if they have infection levels similar to NY in the next month or two due to this immunity - just a guess, though. Also, there is little evidence that playing soccer is a high risk activity - despite the charts I have seen that put it up at a significant risk level. Texas is in a similar situation to AZ and haven't had any large outbreaks associated with training/games. Time will tell, but there is little scientific evidence to indicate soccer is a high a risk. However, I am aslo sure the risk is not 0.
I’ve seen 1 article in Forbes that mentions a study done in the Netherlands. Findings summarized:
However new research has suggested that the risk of ‘close encounters’ during a soccer match is minimal. Sports performance specialists Inmotio and the Dutch Soccer Association (KVNB) assessed player tracking data from every match from the country’s top-flight in the past two seasons.
Of the 482 Eredivisie matches assessed, just 0.2% of matches saw two players exposed to close contact for more than 30 seconds. For the purposes of the research, a close encounter is described as an interaction within 1 meter – the distance stated in the World Health Organization’s (WHO) guidelines.
What’s more, many of these close encounters could be reduced. Between 50% and 80% of all close encounters are attributable to players convening for the results of referee decisions or those by video-assisted referees (VAR) and other game interruptions.
Reducing the time it takes for a corner to be taken can result in a 45% reduction while changing goal celebrations can deliver a 35% drop. The Bundesliga has told players to adopt social distancing when celebrating a goal already.