I am not really attacking either raised beds or no dig method. I just cannot for the life of me see why they have become so fashionable. Both methods involve applying large quantities of organic matter to the soil and this is a fundamental and basic requirement for sustained crop production.
However, adding organic matter does not have to be done in these ways. There is nothing particularly magical about adding amendments to the soil. People have been doing this, probably, since agriculture was developed.
I have just heard about the Sinhalese practice of deep trenching and adding any organic matter to the trench before covering with soil and growing crops. I should not be surprised because it seems that similar methods of growing have developed throughout the world.
Whether you go up; adding organic matter to the surface, or go down; adding organic matter to trenches or even a mixture of both, the common principle of all these methods is adding organic matter.
I dig and I no dig depending upon the needs of the soil. If the soil has had little organic matter added then I will dig some into the top soil and mulch. If green manures have been sown in the autumn I will dig them in in the spring. I will mulch in the summer to conserve water and suppress weeds. I will do this to produce good crops not because it is a fashion.
I have put concrete slabs on end around the allotment as a retaining wall, not because it is a trend or fashion but because I need to retain my top soil. The level of the top soil has been raised because I have added so much organic matter.
Another reason, and this is really why I embarked on raising the allotment top soil, was to enable me to drain the soil because it was water logged for most of the winter.
Raised beds are just a waste of time and effort. There are more paths than growing area.
The gardening philosophy that suggests that soil should not be walked on because it destroys its structure just does not ring true. I was watching "The Victorian Kitchen Garden" for May on YouTube and the gardeners there were scuffing the ground along the drill lines to consolidate it before raking and making a seed bed. This is what I was taught to do when I was a lad. It breaks down the large lumps of soil and allows you to make a really good tilth with the rake.
When I was learning how to grow from my grandfather and father they always firmed the soil in seed beds by treading along the rows and raking afterwards. In this way a really fine tilth could be made fairly quickly. I still tread along my seed lines to firm the soil before a final rake and taking out the seed drills. This technique does not seem to prevent the seeds from germinating.
I tread between the rows to hoe and cultivate along the plants. Removing weeds and scuffing up the soil to slow evaporation seems to be much more important in producing good crops than avoiding compaction.
There are times that I avoid walking on the soil. When the soil is very wet it can be easily compacted and will form an impenetrable cap on the top soil. Also when it is frozen, I avoid walking over it. Otherwise I am constantly walking over the soil. I do usually scuff it up afterwards but that is just to make the soil look presentable.
So I think that the important thing is to add as much organic matter as possible in as many forms as possible and only use retaining walls to prevent the raised soil from falling onto the paths or to enable drainage.
One of the most enjoyable parts of gardening is to improve the native soil. Filling raised beds with commercial sterile composts seems to be a complete anathema to organic growing. These composts are peat based and usually contain inorganic fertilizers. They will grow some good vegetables for a few years but they are not sustainable.
I will stick to using the native soil adding amendments as they become available. At the moment I am using home made compost, horse manure, lawn mowings, turfy top soil and shredded branches.
I am also making comfrey, sweet cicely and nettle tea to use as a liquid manure and pigeon manure as a quick acting nitrogen fertilizer.
I am using the charcoal , which in itself is fairly inert , as a method of applying a slow release fertilizer after being inoculated with comfrey tea. It seems to work for me particularly when I have used mychorrhizal fungi as well.
I must admit I am completely practical about various gardening techniques. If they work I will keep doing them; if they don't then I will abandon them. The only criterion for success is whether the vegetables cropped well or not.
I do what works for me.