No-one is saying that all the tips are practical to everyone. Just because fruit trees or blackberry picking doesn't work for everybody doesn't mean that it isn't a valid tip. It will help somebody and some may see that and think 'I'll try that'.
And some of those people may be poor and in rentals. It doesn't automatically preclude them from picking blackberries or growing fruit trees.
I'm constantly baffled by the assumption that any interest in food, eating pulses or foraging is a niche inaccessible middle class activity in the UK. Most other places in Europe and further afield it's something that most people do, with no class/income divide.
I live in an ex council property on the sort of estate was thrown up on green belt after the second world war. It's about half rented and half owned and many properties have very large gardens that back onto green belt and are hence suitable for planting fruit trees. Many properties, both rented and owned (you can tell because all the rented properties got new roofs and windows a few years ago) have fruit trees in their gardens. So anyone round here, and many other similar places, can grow and pick their own fruit.
There seems to be an assumption from some on here that everyone who is poor lives in a mythical world where there are no cheap supermarkets anywhere near and everyone only has access to an overpriced local convenience store that sells zero fresh food and that any discussion on eating on a budget shouldn't include anything outside that world.
While that may be the case for some, it's by no way the norm, so it's not helpful to sit there sniping at tips going 'what if they can't get to Lidl, what if they can't afford the bus, what if the DCs won't eat pulses, what if they can't cook or don't have any pans, what if the butchers and farm shops are the 'naice poncy kind' not the 'cheaper and better than the supermarket kind' etc etc etc because it's a very tired argument and rather insulting to assume that all people with a small food budget have no cooking skills, will only eat beige and chips and are unwilling and incapable of doing anything constructive to help themselves.
Long term tips are just as helpful as short term ones. 'Teach a man to fish' and all that.