I suspect that in many cases, defibrillators are sited according to the same rule as cycle lanes: they are positioned according to where space is available rather than where the need is greatest.
Thus in many villages, the defibrillator is in what used to be the phone box — unless of course the old phone box has already been converted into a miniature community library or art gallery.
I suspect that most heart attacks occur either in the home or the place of work, simply because they are the two places where people spend most of their time, and tend to be sedentary. In my village, the defibrillator is next to the sports field and playground that is used mainly by children. It is at one end of a village with "Long" in its name, and 10–15 minutes' walk from where the high risk age groups congregate: the Co-op shop, the two takeaways, the village café, and the two pubs (which are all fairly central) and half an hour's walk from the parish church.
This link suggests only 3% of defibrillators positioned outside of hospitals are actually used. ("Outside of" meaning "
not in hospitals" rather than "just outside the hospital"!)
This link suggests public access defibrillators save about 20 lives a year, which is not to be sniffed at.
This link points to a substantial increase in heart attack deaths linked to the pandemic. Some are due to reduced access to diagnosis, some due to reduced access to treatment, and some are due to the fact that the Covid 19 infection itself increases the risk.
A bit of Googling shows the first public access defibrillators were introduced in the 1970, and that by 2014, it was already common for communities to be raising money to get them installed locally. That is way before Covid 19
Of course, it is possible that taking the vaccine increases your risk of a heart attack. If it is a vaccine against something that causes a greater increase in risk then the vaccine is not the problem.
As always, a major problem is that the general public has very little understanding of the nuances of probabilities and statistics, and looks for simple answers to complex questions.
The image below is the number of public defibrillators in the UK by city, just showing the top few cities. At about £1,000 to £1,500 each (plus installation and maintenance costs) that is a lot of money per life saved. Saving life is worth a lot, of course, but whether these public access defibrillators are the best way of spending the money available is a valid question. In my own case, I've had huge amounts of training on CPR and EAR but would have no idea how to use a defibrillator.