I'm no expert, but I live and work in Japan.
As far as I have seen "Shinto as a religion" plays a relatively small role in Japanese society. I am American and Japanese shinto looks almost nothing at all like American Christianity.
Many if not most Japanese people visit shrines (especially on set dates throughout the year), at which time they give a small donation and prayer, but from my perspective this is indeed mostly ritual. Routine you might say.
You could also say Japanese culture has high inertia. People tend to do things because (a) that's what other people do or (b) that's what's always been done. Of course things do change, but without a strong impetus they tend strongly to coast along the same road.
Shinto from a broader perspective, or simply Japanese culture as I am tempted to call it as it's difficult to draw a line, has many other influences other than simply visiting shrines. Festivals, rituals, and so on. But here also I don't see what I would call a "religion" based on a "strong belief" in "higher power(s)."
An example is when a new house or building is to be built, Shinto "priests" are called to perform a ceremony at the building site. Another is the little salt dishes they put around houses and buildings to keep "demons/bad luck" out. Seems to me it's closer to superstition!
Occasionally I come across something like this PDF and it confuses me. It portrays Shinto as very mystic, but that doesn't match well with the reality on the ground of everyday life in Japan, at least through my lens.
Note: my experience is in the last decade and a half. I haven't asked or heard much about the past. It's not a stretch to imagine that "shinto" used to look more like a "belief based religion" some decades or centuries ago.