> I do not understand why smart developers try to figure out how to make transaction even more efficient and on the other hand also enable more spamming?

Developers... which developers? If you mean spammers... they are not developers. They are spammers. They are spamming "uncommon goods" op_returns by the thousands and thousands for reasons I don't understand. Usually at very low <1 sat/vb fee rates which take long periods to get confirmed.

028559d218

bitcoin

A Real SPAM solution: People using Bitcoin

I do not understand why smart developers try to figure out how to make transaction even more efficient and on the other hand also enable more spamming?

Are they corrupt aka. having another hidden motive, are they cognitive delusional or are they some kind of neo luddites that want to protect further work as optimizing a dysfunctional UTXO set will be a challenging task that will occupy them for decades.