There is no unwillingness to report these numbers, and it is simple common sense that when a vaccine is reported in the press to have efficacies of say, 85%, 70%, or 95% , it means that this is the percentage of people who are prevented from getting Covid after vaccination, compared to those who are unvaccinated.
Clearly this also directly informs you that 15%, 30% or 5% of people who are vaccinated will get Covid despite their vaccination status. There is nothing hidden or obscure about these statements!
Contrary to your implication that this is somehow hidden or deliberately obscured information, the mainstream UK newspaper The Guardian published a helpful article detailing exactly this only a month or so ago:
https://www.theguardian.com/theobserver/commentisfree/2021/jun/27/why-most-people-who-now-die-with-covid-have-been-vaccinated
"Why most people who now die with Covid in England have had a vaccination
David Spiegelhalter and Anthony Masters
It could sound worrying that the majority of people dying in England with the now-dominant Delta (B.1.617.2) variant have been vaccinated. Does this mean the vaccines are ineffective? Far from it, it’s what we would expect from an effective but imperfect vaccine, a risk profile that varies hugely by age and the way the vaccines have been rolled out.
Consider the hypothetical world where absolutely everyone had received a less than perfect vaccine. Although the death rate would be low, everyone who died would have been fully vaccinated.
The vaccines are not perfect. PHE estimates two-dose effectiveness against hospital admission with the Delta infections at around 94%. We can perhaps assume there is at least 95% protection against Covid-19 death, which means the lethal risk is reduced to less than a twentieth of its usual value."