In these events he is not standing up against anything. He appears to be quietly proving false statements about his test results and/or his recent travel history in order to manipulate the system to his advantage (i.e. gain the ability to take part in a tournament in a country he is likely not eligible to enter).
Are there many previously young and healthy people ending up in hospital with Covid?
Yes, of course, more than a thousand of children and young adults in their prime died just in US.
https://abcnews.go.com/US/wrecked-lives-families-young-adult...
https://data.cdc.gov/NCHS/Provisional-COVID-19-Deaths-Focus-...
https://nymag.com/intelligencer/2021/05/study-number-of-kids...
On top of they are 66% less infectious when being infected since they clear the virus twice as fast and 40% of their virus particles are dead.
This gives them an overall reduced risk of infecting someone else by 93%.
https://www.medrxiv.org/content/10.1101/2021.11.24.21266831v...
https://news.arizona.edu/story/covid-19-vaccine-reduces-seve...
Q: How long does that reduced risk persist for?
Then read this story:
We can’t vaccinate the planet every six months, says JCVI chief https://www.telegraph.co.uk/news/2022/01/03/fourth-covid-jab...
"Prof Sir Andrew Pollard said there was no point in trying to stop all infections, and that 'at some point, society has to open up'"