As you said, most of us have followed the same path. Many years ago, when I got back into trains in my early thirties, I started with high rail scenicked layouts. After a few rebuilds I had built what I considered a decent high rail layout including scenery. It wasn't long before I said what PRRJIM said, "What now?"
My kids were growing and they would enjoy the trains but got tired of running passenger and freight trains over the same route. Switching operations seemed tedious to them.
The operating accessory bug bit. So my next layout or should I say, layouts, were strictly action heavy but still with some caricature scenery. Nothing too detailed. SWMBO would come down to the cellar only on occasion, but did know when a new layout had replaced the old one.
I found the beauty of a post-war type layout is the ease with which it can be changed without having to do an entire rebuild. Particularly with tubular sectional track. I learned a few tricks in doing these changes. First, do not install track pins in the six rails of the switch tracks. Instead, simply line the rails up and make sure the switch track and the two tracks that meet are secured reasonably well. This way, when the switch track has to be serviced, which it will, it's a simple task to remove and replace it. Second, remove the screws that hold the motor cover of the switch tracks and let the cover simply sit in place. If you must get to the switch drive, it's a lot easier.
Try not to use long sections of track. It never fails that an operating accessory will fit nicely in a given spot. If it needs a remote track next to it, sectional track, be it O27 or O is way easier to work with.
I know I have gone on a tangent, but my intent was to offer an alternative to building another brick sh*t house.
