Sir Crustaceous stated in this speech that life was markedly improved when in an aquatic environment. Is this true, or a desperate attempt to keep Princess Ariele in power, thus securing his position in the royal family?
It's complete nonsense. Triton's kingdom suffers from chronic underdevelopment and endemic poverty caused by his autarkic policies. The economy is barely above subsistence levels. Note that mermaids and crabs alike must cover themselves by scavenging for sea shells, and use scavenged objects as musical instruments. There are practically no manufactured goods and services (aside from the admittedly excellent musicians) are nonexistent. This state of affairs can only be maintained by state propaganda disparaging the outside world and discouraging any contact whatsoever.
Sir Crustaceous is 100% accurate in his speech detailing the benefits of aquatic life. In addition to the care-free lifestyle enjoyed by the citizens of Triton's kingdom, they also experience much greater safety than their counterparts on land, as there is little risk within the kingdom of being filleted and fried. Long live King Triton!
Edit: spelling