There's also the "going with the flow" factor. Depending on your region / industry, it may well be the case that most of your peers will already be using Esri products. Certainly the case in US local government. Using the same products means your work is almost certainly compatible with others.
The thing with Esri is they do so much. It's hard to really compare, because "competitors" may only compete on a few items, not the whole swathe of offerings. The web and mobile options with Esri are top-notch, and I enjoy using them most of the time. Desktop, though? I use QGIS almost every day, since I'm running Linux. I boot into Windows when I need to use the Parcel Fabric, which is something I am absolutely happy to pay for, but the rest of ArcGIS Pro? I don't really need it.
I would encourage you to narrow down what specifically you are looking to do in GIS, and see how Esri and alternatives meet that particular need. If you're doing serious analytical work, you may not need desktop GIS at all! Some of the best maps I see these days are produced entirely in R.
- Josh Carlson
Kendall County GIS