15 years ago I remember a lot more experimentation was encouraged and a lot less process. I could have an idea and get an enthusiastic "go for it". I could improve the way we deployed code. We had some semblance of "agile" but it was much more informal. I had passwords to everything.
Now everything is locked down. Everything is decided. The technologies are chosen, the process is complete and rigidly enforced. I pull tickets off the board at the start of a sprint. I finish the tickets. Day in and day out.
The main difference I've experienced is how people take themselves so seriously. The incessant hustle culture is so laughable, especially when you're working on a dumb app.
The tech itself is also an issue as you said. 15 years ago I was writing code, or at a minimum reading code to make it work. Now it's all these off the shelf AWS/GCP things that sort of work but you spend days to glue them together. You keep relearning the same thing because they all use slightly different versions of the same scripting language just because.
I can't tell the last 3 companies I worked for apart. It seems like a large percentage of companies today operate the same way. "Agile with 2 week sprints" never ending death march.
(As someone who often works for smaller orgs) It doesn't HAVE to be that way. None of the smaller orgs I've worked for use those systems. Only the big techy ones with a lot of bureaucracies do. They pay better, but you do much less, and push around a lot of paperwork instead of code. There ARE alternatives. Your average small town non-IT company probably still needs developers here and there, and they won't have the resources for the overhead of Agile bullshit. You'll typically have the keys to the kingdom and have to make shit work with very limited resources and a tiny team, but it's a heck lot more fun.
I tried a big corpo job for a bit, ugh, never again.
I was in tech for 35+ years - yes, I'm old. I'm out now not because I don't like the work, I really do and I'd prefer to be doing interesting work. I'm out because I'm tired of the interview games that are played now - that and I've pretty much got my retirement nestegg saved up.
Tech has definitely changed. Having to go through 8 or 9 rounds of interviews for one position only to find out you weren't selected at the end (that is if they don't just ghost you) wasn't a thing when I got into this line of work. In fact most of my early jobs I got after only 1 or 2 interviews for maybe a total of 90 minutes.
Part of it is that companies are just so damn afraid to hire the "wrong" person that they just can't make a decision. Part of it is because there are so many people looking for tech jobs right now that companies feel like they can play these silly games. More people need to refuse to play.
I'm downright awful at the interview game and it causes me so much anxiety that I turn into a complete moron when I have to code in front of someone. Also the process involves completely different skills than the job actually requires.