I was obsessed with Thunderbirds and Captain Scarlet as a kid.
In the end I got the box set on prime of Captain Scarlet, as on TV they only ever showed the same episodes over and over. I discovered on watching all 32 episodes that there was a reason for that… they were terrible. The first episodes were quite good but rapidly they clearly ran out of ideas. I heard that Silvia Anderson tried to convince Gerry Anderson to have more character development, even, flawed characters, but he’d have none of it and the series kept churning out the same story every episode. This worked with Thunderbirds, but not so well with Captain Scarlet.
The final episode “The Inquisition” breaks with this and is rather crazy and incredibly camp.
Most Gerry Anderson stuff is about the cars, trucks and planes. The characters are secondary. Captain Scarlet had a whole bunch of cool transport, as outlined in the Captain Scarlet Haynes Manual!