I did a tour with a respected company, frequented by solo travellers. We had sag and mechanic support and although it was camping, they arranged all the catering.
The route , from Bordeaux to Barcelona was clearly way-marked every day and we were given route maps.
Of all my tours, this was the one I remember least. I had no exploration or navigation to do, no decision making, no chance encounters and little contact with people along the way.
I much prefer to do my own solo travel. During off peak (May/June and Sept), you can find accommodation in any small town and most villages. You can travel very lightweight with no more than a pair of small panniers and a barbag. You are never too far from a bike shop or cafe.
You can tour from a fixed base or move along as you like. You can nip on a train to carry you to a different region. Small regional airports serviced by budget airlines get you out into the countryside with no big city worries.
If you want a tour company, a UK-based one may be easier then a US one.