It is explicitly the policy of the chinese government to not try to take Taiwan by force unless some red line is crossed and the one china 2 systems policy is irreversibly violated.

Since the policy hasn't been irreversibly violated, the mainland hasn't invaded. This has been the system for the past 70 years and has been maintained by every Chinese administration, including the current one which has run for 10 years already and has still maintained the same 1 china 2 systems policy.

Of course, due to many factors, such as the fact that an invasion is still possible, the military build up along the first island chain by the west in an attempt to encircle china, and the ability of western powers to cut off oil imports to China by blocking off the straits of malacca, the mainland builds up naval power as quickly as it can.

However! As other commentesr have pointed out, these barges are actually useless as military equipment, as can even be seen in the photo that is presented. Why would a country with aircraft carriers and a virtually unlimited supply of drones/missiles rely on such comically sinkable bridges to roll in tanks into Taiwan?