@Eleganz The current prescription charge is £9.35 per item. Yes there are exemptions for some chronic conditions but not sure that removing those would achieve what you are aiming for
As @Shiraztonight says, in theory people pay, but over 90% prescriptions - and probably even more when you look at it on a £ basis - go to people who don't pay, either because of age, socioeconomics or illness type.
This is the kind of misconception that tends to lurk in the heads of healthy(ish) people, who don't realise that a HUGE majority of NHS and social care spend goes to support people who are not in work, not in good health and in many cases will never recover.
That is still a good thing - everyone deserves care, and any of us might find ourselves in that situation one day.
But it also isn't sustainable to have a shrinking pool of people in work, paying a growing amping per head for a growing pool of people who have had far more paid out on them by the government than they ever paid in. This group includes most pensioners, many people on benefits, and also people with lifelong health conditions (I am in this.last group, so am not making a dig, but am wanting to be pragmatic).
Meanwhile people who are in work are struggling to get a basic GP appointment, can't get support without huge waiting lists or going private if their kids are having major mental health troubles or need braces, and know that the money will be gone in a few decades when they need it.
As a social contract, this doesn't work.