Agree, vaccinations should focus on the immunocompromised and elderly. That was specifically 39% effective against the Delta variant. Again, the shots are effective against symptomatic disease, you may still get COVID - especially with so many unvaccinated out there.
From the same article that states the "39% effectiveness..."
Covid-19 vaccine is just 39% effective in Israel where the delta variant is the dominant strain, but still provides strong protection against severe illness and hospitalization,...
...the two-dose vaccine still works very well in preventing people from getting seriously sick, demonstrating 88% effectiveness against hospitalization and 91% effectiveness against severe illness, according to the Israeli data published Thursday.
CNBC - https://www.cnbc.com/2021/07/23/delta-variant-pfizer-covid-vaccine-39percent-effective-in-israel-prevents-severe-illness.html
And yes, boosters may be required each year against the prevalent strain. Current studies suggest that getting COVID will potentially give you immunity from 5-8 months. But, you run the risk of other COVID complications, which are not fully understood yet.
If you can, get the vaccine even if you've had COVID.