Yep, that's exactly my strategy!

However, this works opposite by not hiding in the mass. The thief hides in the mass, as bikes themselves don't flee the scene when a thief is in sight. So the trick is to find a good place for my bike. As I have a fragile racing bike (old and cheap but technically in good condition), those massive outdoors parking systems are not good places. People pull and push to get their bikes out, and a racing bike wouldn't survive that for long. So I find places where my bike is safe.

It's always fun to see that I park my bike in an empty spot, and after an hour or so the space if filled with other bikes.

During my student days, I always made sure to check if the bike rack had a bike that looked prettier than mine and had worse locks.

Now that I ride a much more expensive cargo bike, I don't worry about it anymore, and it hasn't been stolen yet. Are cargo bikes less attractive? Hard to believe, but it seems to work.