Worst project I worked on was fixing up and optimizing a clients legacy Magento app. this thing had leftover code from a few different development teams, and then my company had to make it run better. We outsourced much of it, and it wasn't using a proper git setup. in order to do absorb at all, we had to SSH to a dev server, work directly, and pray another person on the team want working on the same file or breaking something else.

It is not easy to fix the errors of Magento website. As, Magento has the ability to be the worst nightmare of your life. That's it's developers usually cost higher then that of Wordpress developer.
However, most of the times it is actually because of the hosting server and not the development end that causes the error issue.
So, I only recommend my Clients to use specialized hosting for Magento as their are companies like Cloudways who provide such sort of hosting experience.