I think there is a balance between doing it yourself and calling the professionals. If it’s a straight forward manageable task and you have the correct tools and knowledge, why not.
For example, I wouldn’t climb an 80 foot tower, pull and terminate 120 pairs of Ethernet cabling or try to terminate fibre connectors.
While working onsite I was asked “Why bother?“ or “We’ll get someone else to do that”. Some people feel that some network tasks are too menial or beneath them. I’ve had some network technicians ask why I would bother doing ‘that kind of work’ when you have had various certifications.
There are many answers; I like the variety, I enjoy keeping my skills sharp, and the job gets done quicker. I find I can add more value to a design or install since I have physically done the work as opposed to just reading the materials. The bonus is that when I watch people do incorrect installations, I have more things to look for when troubleshooting problems.
Here’s a simple example: we had to pull and terminate 3 Ethernet cables as part of an install. The technician said “let’s just call the cabling company to do it”. I asked how long that would take and he responded 2 to 3 days. I reminded him that I was only there for the day and added that it would not take us long to pull three cables 20 feet and terminate them ourselves. The cables were a straight run in the cabling trays above our heads.
Just a quick disclaimer; if you have no experience terminating cables, do not practice or learn on your production environment. Fortunately I have been terminating Ethernet cables for over 20 years, so this is a fairly simple process. I went to my vehicle and got a spool of cable, some RJ 45 connectors as well as my crimper. Fortunately, I had assumed that I might need to do this type of work and had prepared myself with the proper supplies and my vehicle.
Flashback; I will never forget working with network consultants at a new build and I was the only one with tools, a hard hat and my government safety certificates, even though everyone was told this is a construction area. The other consultants were limited when, and where they could work where I had the run of the place.