- IF the cardiac arrest risk indeed rises 5x
- AND that is not related to study effects (perhaps the risk of those athletes using performance enhancing drugs which you presumably aren't using was many time higher than 5x)
- AND the chance of of 5x higher cardiac arrest risk is higher than the increased risk you run of dying from COVID
- AND the risk of booster shots increasing cardiac arrest risks (which has not been proven yet) is indeed exponential, which seems quite unlikely at first glance (since the dose of boosters is only increasing linearly over time)
And several other factors I can't think of off the top of my head. It looks like you are assigning a very high risk to booster shots and assigning a very low risk to dying of COVID. Given the amount of people who have died of COVID vs the amount of people who have died from booster shots this seems like a misassignment of risk.
The comparative disease vs vaccine risk assuredly differs between fit young FIFA players and obese geriatric persons. It may well be that even in the former case the vaccine reduces overall risk, but surely the effect is smaller than in the latter group.