You are an outlier. Your personal interests and professional skills are tightly aligned in a way that very few other people ever develop themselves. To expect to find a large pool of candidates who are similar to yourself is completely unrealistic.
It takes a certain type of exceptional individual to make a small company work. There are only so many of those people in the world. As companies grow, expectations need to change. Primary among those is the expectation that a new employee will be able to perform a number of different roles. The reason that the prior generation of the company was able to pick up many roles is because it happened organically. As tasks needed to be completed and as new challenges arose, people stepped up to the plate and tackled them because they had to.
The challenge that you are currently facing is that there are too many IT related tasks to do, and not enough people with the skills to do them. The solution to that challenge is not to expect engineers to become IT people. The solution is that management needs to create an IT department, or an IT position and staff it with IT people. Just as you would not expect an accountant to perform engineering work, even though both involve math and numbers, you cannot expect someone whose focus is on engineering to perform IT work.