Your wiring method clearly is working for you so far. That's great. I like your mention of tugging. I'm a believer in the "tug test", at appropriate forces for each connection being tested.
Not soldering under the layout sure would be welcome. I soldered all my stuff, most of it 30 years ago. It was hard then. It's getting harder for me to do now, as I rebuild my layout after a move.
Mechanically made electrical connections not subject to a lot of flexing are more likely to fail over long periods of time, not short, due to corrosion or surface oxidation. Using good quality connectors and methods is your best protection against that.
You probably know that the telephone companies were pioneers of solderless connections. They found properly made solderless connections were more reliable than soldered ones. "Properly made" is critical. Enough contact pressure is required.
The contacts need to cut into the wires and create a tiny metal to metal contact zone sealed against air and oxygen, because long term failures usually are the result of oxidation of the metal at the joints. Surface oxidation insulates the wires from one another, especially in damp or other corrosion prone environments. Oxidized metals become insulators.
You'll learn how good your connections really are over the next 20 or 30 years. If they stay trouble free, then they are really good. If you begin having problems, they aren't. So, it's important that you are doing a quality job now. It's to your long term benefit.