A lot less than the roads for automobiles, and I regularly use the bike lanes in Sweden during all seasons and have no issues with that despite being originally from a warm country.
What a weird rant to come after bike lanes because "they are expensive and just virtue signalling", jesus.
Bike lanes are like gym memberships, people like the idea and buy into it, but in reality they are too lazy, and don't have the time to actually do it. And it just ends up being a waste of money on duplicated infrastructure, because you still need to cover 100% of the capacity in public transport for the rainy days.
This was me before an ebike. I now use it absolutely every day, when the weather allows.