dont large platforms scrape for encrypted hashes to decrypt with super computers in the future?

i recall one of my coding projects in the past was an application that encrypted plain text messages with a pass key, you could also save the message with a custom file extension so you could, in theory "hide" it by making it seem like its a borked jpeg or some other file format.

i created it with GDscript and just used GDscripts default encryption method, i dont know if thats truly secure. probably not.