I just want to say, I am just speaking what I think. I have no clue as to the real reason why TTTE went CGI I'm just saying what I think and from what I've heard from some youtubers. I would say its bc of 2 main reasons: Time and effort(one category), and Quality. FIRST is time and effort. The reason for this is because it would take a long time for the (Idk ppl who make the sets) to change them every so often for new scenes like every second. Considering that accidents happen which could ruin the entire set making them have to redo everything again. (Like not train accidents, but accidents like tripping and hitting the sets) And now quality. For a fact, the studio making the model series wasn't actually very wealthy.(From a old youtuber I watched said) and because most episodes had the engines going through accidents would eventually cause them to wear down over time. And it (probably) costed a lot to keep the engines in running order after dunking them in all sorts of materials (Like grass, sand, mud, dirt, and specifically water) which caused them to rust. It would be faster and easier in CGI because none of the reasons would mean anything to computer animations. But there is NO REASON as to why they went AEG
