Well Miami is made up of various cities and they are all interconnected. The City of Miami itself has a population estimate of 453,579 with a density of 12,604.32/sq mi (4,866.49/km2) which is interesting because its closer to Amsterdam's actually. Miami-Dade County is roughly 2,751,796 with a density of 1,449.8/sq mi (559.8/km2), with the Miami Metro Area coming in at 6,158,824 (Miami-Dade, Broward, and Palm Beach counties). Amsterdam has 851,573 in the municipality itself, with a density of 5,135/km2 (13,300/sq mi). The urban area has 1,351,587, the Metro region 2,431,000, and the entire Randstad is 8,116,000 (Amsterdam, Rotterdam, The Hague, and Utrecht). Miami only as a city has an area of 56.06 sq mi (145.20 km2) but this isn't combined with other cities like Kendall, Hialeah, Opa Locka, etc. and the Amsterdam city area has 219.32 km2 (84.68 sq mi). Altogether Miami-Dade County has 2,431 sq mi (6,296 km2). The Randstad has an area of 3,043 km2 (1,175 sq mi) and the Miami Metro region has 6,137 sq mi (15,890 km2). All of this can be found at https://en.wikipedia.org/wiki/Amsterdam and https://en.wikipedia.org/wiki/Miami and https://en.wikipedia.org/wiki/Miami-Dade_County,_Florida and this website by Arcadis also shows interesting statistics between Amsterdam and Miami that you have to click through https://www.arcadis.com/en/global/our-perspectives/sustainable-cities-mobility-index-2017/comparing-cities/?tf=tab-people&sf=uptake_of_active_commuting&r=all&c=amsterdam,miami
Both cities are also very humid and rainy, with Miami averaging 132 rainy days and Amsterdam 182 (https://weather-and-climate.com/average-monthly-Rainy-days,Amsterdam,Netherlands). The rain doesn't stop the Dutch from cycling. Of course heat is a problem in Miami, but that isn't something some proper shade can't address. Seville, Spain has temperatures that often exceed Miami's and they have a healthy cycling culture because they built the infrastructure that allowed a culture to take root, rather than being relegated to a fringe culture.
Amsterdam and Miami are both flat, both concerned with sea level rise, and both populous. Actually Miami seems to be less concerned, otherwise they wouldn't be building high-rises still with projections of going underwater. They had Dutch water officials come to try to help them but it seems to be a moot point. Miami's pattern of development mirror the rest of Florida = favoring developers who want cheap land, therefore less encouragement of infill and greater distances, fueling the autodependency. Amsterdam's patterns of development are the opposite, favoring local clustering, density, and short trips. That's why bike-train connections can help Miami to bridge that distance gap and let go of autodependency. They need to just focus on building extensive transit and protected cycling infrastructure in lieu of continuing the same trend of adding asphalt. However they are usually more interested in technomanagerial solutions to their mobility problems, like autonomous vehicles which are still just vehicles.
It’s important to also note that bicycles perform the best between 1-5km of distance. They are great at local connections rather than distance. For this reason the train provides that extension of easy and convenient travel. Then the train stations have to be spaced appropriately in order to accommodate this accessibility and take away the incentive for people to drive to the station and expect free parking. Metrorail provides that connection to the regional commuter Tri-Rail making it the first access point on a bike-train system in Miami. But safe accessibility for bicycles to the train stations is the huge hurdle. Unless you live very close by, cycling to the station for the risk averse makes it a non starter.