That profile in particular is interesting. The first two tweets appear to be human originated, and date from December 2021. There are no tweets from the account until seven hours ago, and all the tweets after that point are spam.
Several options:
* Spammers creating accounts and posting human posts in advance knowing they'll be used for spam in the future
I wonder what these strings are. Some sort of an ID? Or maybe to make these tweets sufficiently different from each other to avoid triggering spam detection?