As a long time Pythonista I was going to push back against your suggestion that Python didn't have much momentum until recently, but then I looked at the historic graph on https://www.tiobe.com/tiobe-index/ and yeah, Python's current huge rise in popularity didn't really get started until around 2018.
Yes, TIOBE is garbage. The biggest problem is that because they're coy about methodology we don't even know what we're talking about. Rust's "Most Loved" Stack Overflow numbers were at least a specific thing where you can say OK that doesn't mean there's more Rust software or that Rust programmers get paid more, apparently the people programming in Rust really like Rust, more so than say, Python programmers loved Python - so that's good to know, but it's that and not anything else.
From what I can tell it wasn't as prominent as it has been recently, with being a popular pick for random projects that weren't just gluing things together. The big companies that used it were perfectly happy specializing the interpreter to their use case instead of upstreaming general improvements
(TIOBE's methodology is a bit questionable though, as far as I can tell it's almost entirely based on how many search engine hits they get for "X programming". https://www.tiobe.com/tiobe-index/programminglanguages_defin...)