Sure, long term they absolutely are. But when they potentially start to flame out this early it doesn't even create trade chip value.
https://www.mlb.com/news/mlb-international-prospects-signing-day-2023
Like you can search up the seasons for the top 15 here, and Bonilla is having pretty easily the worst season of any of those signings besides Shim who has been injured. Salas is having a poor season, but he is literally in high A ball as an 18 year old so that can't be compared to Bonilla's struggles two levels below that. Yeah international signings can be a lottery, but relative to the rest of the international guys signed that year he's also really bad. Lots of that top 15 are having solid value raising seasons.