I'm a self-taught developer at global market leader company. I worked on the business side for years and built quite a few internal apps end-to-end completely alone. I had no choice but to follow good practice to maintain them alone.

I was quite reluctant to join the dev team, it never had a good reputation, but eventually decided to give it a go. Agile and estimations, spill overs, etc is such a pain in the ass, it feels like a pseudo-science. A lot of people spend a lot of energy on just this administration while we are way behind on many other things, like proper unit testing, good quality documentation, well established CI/CD. And everybody is focusing so much on the estimates, tickets like this was the end goal. I want to change their approach but there's a long way to go.