I don't mind the constant shifting and relearning of tech. What bothers me is having to split all of that effort with all the other skills that are also demanded by virtually every software company out there. It's all the product management, meetings, setting expectations, etc., which has more to do with business management. The industry is adamant about this. They insist engineers also manage themselves like a small business, and failing to do so will kill chances of promotion.

If engineering was focusing on building, then I can deal with anything technical, that was the point of doing many years of CS, but when it's also managing business it becomes unbearable at times. Meanwhile the non-technical people have none of these pressures to keep up with exceedingly hard technical concepts, and they still demand that engineering isn't just about building but also about solving business problems. It is indeed very tiresome.