Thank you very much for all your answers. From what I see, most of the answers match my practice. I don't entirely agree with
@bishblaize. I think GTD fits everywhere - it's just more challenging to implement in some situations. We all know the standard example of changing a tire - these are simple to implement situations. Some - especially in hmm... more creative professions - require rethinking. In programming, the problem comes down to two things: we need to have a list of things to code - as mentioned by, among others,
@Oogiem or
@cfoley and often such a list is both reference material and a list of next actions or its inspiration. We do not move some items directly to our list of next actions because they fall under the 2-minute or more-minute rule (Allen set 2 minutes arbitrarily, but he admits that for other people it may be longer). In my opinion, regardless of whether someone consciously uses GTD or not, they still have to follow the same rules - sometimes just in a very ineffective way. If we do not use GTD, we store amorphous ideas in our heads and when we take action, we still have to clarify them and divide them into subsequent actions. But with much more effort and the risk of forgetting something.
I also agree with
@Oogiem about contexts. When Allen wrote the book, there were no smartphones, remote work was not that popular and the last dinosaurs lived in the world
Hence, the contexts were closely related to the physical place and device. In my opinion, the emphasis today falls not so much on the physical place, although it still counts (e.g. office, errands) or device, but on a certain abstract concept connecting several "ancient" contexts. Take, for example, reading a book on Kindle. I have a reader, I have an application on my smartphone and on my computer. I can have the following contexts: computer, smartphone and reader. Or I can combine them into one: Kindle under which the three above will be included. The context may also be a certain thematic area: the application we are writing, the room we are renovating or a group of people we meet or work with. The beautiful thing about GTD is that it is so flexible and unorthodox that it can be used practically everywhere.
Thanks again for all your replies.