I mean, the 100 USD bill is NOT the highest valued bill in the world, that belongs to the former B$10000 bill (withdrawn) from Brunei (I’m serious, this exists) which is worth $7874 and yes it’s a single bill, also converting to around £5803 & 6677€ respectively. Like why does this bill even exist when it’s hard to encounter, given that Brunei is a petro-state, it comes as no surprise.
The second highest valued bill is Fr. 1000 ($1278) or £942 & 1084€ which isn’t a surprise for Switzerland to have that due to how expensive it is over there. But, it’s difficult to obtain even in Switzerland and has advanced security features making hard to counterfeit due to its high value (x12 times of $100) but they sell stuff that’s over Fr. 1000 anyway so it makes sense for them to have that.
The reason why they are barely featured in crime movies or mentioned in real crimes relating to counterfeit money is because of their obscurity and the fact that they don’t know both exist (but it does, although either really hard to get your hands on it or ceases to circulate) however still retains their face value. The Swiss Franc is deemed a “safe haven” currency while the US Dollar isn’t.
For a very long time US currency did not have a lot of effective anticountergeit measures compared to other countries, and there is a massive amount of US bills decades old still used for transactions. Even the sheer amount of bills being used makes it easier to slip in some counterfeit in an otherwise valid bundle of cash before the fact that it is easier to counterfeit older US bills.
A lot of it is momentum from that, and $100 bills being a great value to volume with lower security measures compared to other currencies. Especially if counterfeiting older US bills.
It’s also one of the reasons why the Swiss Franc keeps updating their currency every decade or so (new issues deeming the old ones void) while the US Dollar remains the same for a long time.