At no point, no strain of Covid was *likely* to kill anyone without multiple severe co-morbidities. And while the possibility exists for an unprecedentedly deadly variant to emerge is possible, neither is it a certainty nor there is anything you can do to stop it. So why worry?
What's the line from Fight Club; "Over a long enough time line everyone's survival rate drops to zero". Stop worrying and carpe them fucking diems.
It's not likely to kill you on an individual level, even more unlikely if you're "healthy". However, on a large population level, simple math tells you how devastating a small percentage can theoretically be on a large enough base population. Actual reality tells us that 800,000 and counting are already dead in the greatest country on Earth and there are still people who don't want to take this seriously. It has overcrowded our hospitals to the point where they don't function properly and people can't get the proper treatment for their other "normal" ailments. That is why you worry.
The possibility for a worse variant to emerge is present, and the more people are unvaccinated, the more likely that variant is able to both arise, and spread. That is why you worry.
Over a long time, everyone's survival rate drops to zero, and while that is true, this is the what the human race has been trying to forestall for the entirety of its existence. Overcome nihilism and maximize the health and life of the species. We don't do that by resigning the old and sick to death and YOLO'ing along carefree. There is no diem to carpe when an entire metropolis' worth of people die unnecessarily in 2 years, and most of those deaths could have been prevented with minimal effort.
You're in the UK, which is fortunate to have a high level of full vaccinations and boosters, which contributes greatly to the decoupling of infections from deaths. It's a good effort, and one that should be more closely followed. Unfortunately, not all countries are that fortunate, and an Alfred E. Neuman, "what, me worry?" approach to public health has not historically been a good strategy, nor is it in this case too.