Hi Tone -
Trekking in New Zealand was something that we admired from a distance when we were there many years ago. Even did just a tiny bit of the Tongariro Crossing the wrong way. Went up and came down northwest side from the parking lot to the hut and back. Did see a volcanic vent, but there was a lot of fog and clouds, and we even missed the trail for a few minutes. One sign was misplaced. For sure, Switzerland is quite a contrast, with well- marked Wanderwege.
Good to here about your level of experience. When I talk about walking in Switzerland with friends from the USA, I start with the statement that "Walking is a legitimate form of public transportation in Switzerland." It takes them a moment, then they figure out what I'm talking about. ;-)
Then I go on to "A level trail in Switzerland may go up and down at angles up to 30 degrees from hrizontal," and note that the hiking times on the Wanderweg signs are correct for me only on the less hilly trails, therefore, the Swiss walk up and down hills at the same rate as on level ground.
You obviously don't need those warnings. ;-)
To be serious, the tools that I linked earlier may be useful for helping you match what you are capable of to the topography, as you note. That is my reason for asking:
<<"As for maps, I must admit I have rarely used topo maps, certainly would
say we are not experts at hiking, we just know what we are capable of.
Very much appreciate you asking.">>
The Switzerland Mobility site offers a level of detail on selected "main" trails, such as the National Routes that includes height profiles, accommodation, and interesting sights along the way.
The trails with information are the ones marked with heavy green lines and often numbered on this map:
Click on any green line and a a menu opens on the left, with relevant statistics.
Click on more, and you get a detailed map and a height profile:
I know your request was for "less crowded trails" and perhaps these trails are not empty of fellow hikers, but they are selected for good views, features of special interest, or historical significance, such as the Via Jacobi ( The Way of St. James), an ancient pilgrimage route.
On the Swisstopo online map, the color codings are useful to the degree that the blue marked trails require technical climbing. Not many of those near Solothurn, but, of course, they are plentiful in the Bernese Oberland:
Red trails need good boots and hiking staffs, but I suspect that you don't take even an easy hike without them. I don't The topos are available on a smartphone app, and, of course, paper maps.
If I hike in difficult terrain, due to age and arthritic knees, I have to pick my trails carefully, and will choose between trails to the destination so that I avoid the most extreme climbs and especially descents, as well as trails with significant exposure. The topos are useful for that. I still carry paper topos on those hikes, now rare for me. Due to the excellent wireless phone coverage across the country, my Swiss friends just use the smartphone app.
The best known books about hiking in the Alps are by Kev Reynolds.
There are various editions and variations.
Do a search for "Walking in the Alps."
By the way. we all forgot to ask when you are traveling. Time of year matters for Alpine hikes, as you know. Hiker density varies by month, as do trail conditions at higher altitudes.
I hope you can find the less crowded trail that you seek. Local tourist offices are abundant and usually have someone knowledgeable about nearby trails.