"No dig" in Pots

Compost just isn't a very good growing medium for the longer term. In containers it seems to gradually lose its structure whatever you do. Perlite, bark, grit etc. all help aeration but eventually the organic matter in the rest of the mixture decomposes into dust. This leads to compaction and lower ability to hold water and air, which is bad news for roots. As has been said, in a container you don't have the insects or microbiome as you would in soil. Compost applied to the top of the container is just going to sit there and gradually break down with no structural effect on what's underneath.

Your post above ttt makes me wonder at what size of container does compost turn to soil, I have made my own soil by mixing vegative waste and course sand, made up in builders bag so about a meter cube I have had good crops from this for four years and it still looks very good, there have been other more prominent examples such as Inverewe Gardens and The Eden Project where soil was artificially made with outstanding results, but as you say, with smaller containers the contents deteriates