I have almost 30 years of working under my belt, and as I commonly tell people, I love my Job, but hate the Industry, and here's why:
When I started out (mid 1990s), Corporate IT was still very much mainframe based; Desktop PCs were just starting to appear on office desks. I had the good fortune to work on both early on. It was very much a fast moving environment where keeping things running was the only thing that mattered. We were the 'gurus' who knew how this stuff worked. Stuff that to most people was incompressible. The internet as we know it now, didn't exist. If you were lucky enough to be able to connect to it, most of the places worth visiting were FTP sites. There were a few websites, but nothing of substance. USENet existed, so did IRC and Gopher. You had to put the effort in to get driver updates, and new software to solve a problem.
Without easy access to information for people to solve their own IT problems, it fell to others who were prepared to put in the hours to learn the systems, and read the books. We were the gatekeepers of this wonderful new world.
However, all industries grow up, and IT grew up so fast it was alarming. Overnight it felt that everyone was getting an IT related job, and new associated professions were appearing all the time. Whereas it was just us SysAdmins and a few managers happily spinning the plates and keeping things running, there was suddenly Tiers of Middle Managers, Project Managers, IT Security, Operations, and Developers who only knew their IDEs (or text editors) and didn't even know how to use the system they coded on. Each platform had it's own ship of people doing discrete roles. What was once a nice lean new-frontier of discovery became a bloated enterprise of form-filling and endless meetings, with pointless authority figures whose only reason for existence was to slow things down.
This massive influx of people also brought in people who had no right working in the industry, and a lot of things went wrong, which resulted in the biggest issue I have with it.... a lack of trust. It doesn't matter that I have decades of experience on system X or Y, some bean-counter or form-filler will force me to get my work checked and approved, each and every time because that's the process now. No other industry with experienced veterans would treat them like this, but in IT it's considered normal. I am sick and tired of explaining to people who have no technical acumen at all, that my suggestion, design, or solution is based on my extensive experience only to be basically told 'yeah well, we will check with other people anyway as we don't believe/trust you.'
I think IT is a horrible industry now - and because it pays well it continues to attract people who have no business being in it. All I do now is count the days before I can exit it, and do something better with my life.
I still love computers. I tinker with them every day, I write code my own enjoyment and love fixing hardware, but the industry I use to love, now sucks.