Are Bikes Legally Faster or Just Faster (and What Difference Does it Make)?

As a bicyclist who rides for both recreation and commuting, articles about bike-vs-car speeds catch my attention. Here's one backed up by data! Yes, actual data (because, you know, data matters).

However, I have questions about the data. From my own bike commuting experience, I fully accept that a bike can be as fast as a car. However, there are only two ways that a bicycle can actually be faster than a car.

1. The bike has access to different routes than cars. There could be bike paths that cut through parks, across rivers, etc. that cars can't drive on. This allows bikes to bypass congested streets and intersections. There could also be dedicated bike lanes along the roads that give bicycles different legal rights. I experienced this on a recent visit to Washington DC. There was a path near our hotel that went past the airport, through a park, and over the river with no stop signs. It was a shorter and faster trip to the National Mall than the best car route.
2. The bike uses the same routes as cars but passes on the right at every traffic signal. In heavily congested traffic, this allows bikes to get ahead of the cars. When traffic is stopping every few blocks, this can create a significant time advantage for bikes over cars. I've also experienced this in a variety of cities.

So here's the problem.

Under #1 above, too many cyclists think that sidewalks are legitimate routes for bikes. In most cities, that's illegal. It's also dangerous when there's pedestrian traffic. To clarify, I'm talking about actual sidewalks, not multi-user paths. Legally, those are two different things.

Under #2, in the absence of dedicated bike lanes, passing on the right is usually illegal and dangerous.

So when "Data From Millions of Smartphone Journeys Proves Cyclist Faster" I'd like to know what percent of those "millions" of journeys were completely legal. Based on my personal experience biking and talking to other bikers, I'm suspicious but I don't have data. Even if I had their data, I doubt that it would show whether or not the biker or cars broke any laws.

That leaves me at an impasse. Without data, I can't find evidence to support or contradict my suspicion.

That brings me to the second part of my title: does it matter?

Let's assume that I'm right and a large proportion of the "bikes are faster" data is from illegal riding. If the law is rarely, or never, enforced then is it really a law? The last time I saw an officer stop a bicycle for riding on a sidewalk was when Barney Fife stopped the spoiled kid in downtown Mayberry. I've never seen a bike stopped for passing on the right. If our culture accepts this sort of biking, then maybe it doesn't matter if it's technically illegal and it's fair to simply say "bikes are faster".

On the other hand, what if you're the insurance company that provides workman's compensation or liability coverage for Deliveroo? If a delivery rider gets injured or causes injury, then your company's financial responsibility could change if the rider was breaking the law. Even if "bikes are faster", you might want to encourage the use of cars if bikes are more likely to break the law.

I would argue that the legality issue does matter. Now how do we get the data?