Three weeks ago in Nice, France it was a fraction of a second away from two A320s crashing [0] and possibly hundreds of deaths, similar to Tenerife disaster [1].
Investigation is ongoing and many factors are at play (bad weather, extra work for ATC due to that, confusing lighting of runways etc) but also, from French media reports, there used to be 15 people per shift 5y ago in Nice ATC, now there are just 12, and traffic is higher.
Many people left the profession during Covid and haven't been replaced.
Mistakes and disasters happen, unfortunately the safety we have while flying today has been written in blood, but there is no major understaffed ATC and undertrained pilots in general as mentioned.
15 down to 12 in 5 years with more traffic is not out of the question with advancements in technology but of course, if there is a report that shows understaffing then absolutely it should be addressed straight away and it will be, by the French government.