So you think Serbian is trying to become a more 'simple' language? And Serbian doesn't use locative?

I think they're trying to be different from Croatian standard xD "Dakanje" is actually more "complicated" than infinitive it involves a bit more words and changes the sentence xD

Also, it is impossible to use "dakanje" in some constructions instead of infinitive – Ona neće jesti- Ona neće da jede. The first one means "She won't eat" while the other one means "she doesn't want to eat".

All Štokavian standards (Bosnian,Croatian,Montenegrin, Serbian) officialy have the locative case, but in reality the locative of singular is almost always equal to dative but with a preposition . Compare: Pisati pismo prijatelju – Misliti o prijatelju, Posvetiti vreme poslu – biti na poslu

Štokavian plural locative was alive in some Štokavian dialects but in east-hercegovian it merged with the instrumental case. Ironically – that  dialect is taken for the basis of all 4 štokavian standards  ;D

So, to be honest, no Štokavian standard has the locative case in it's full form.
Dative is fully alive only in singular declination. In plural, it is mixed with instrumental. ("Dao je svojim sinovima" instead of "Dao je svojim sinovom" )
Therefore, it means that the plural instrumental is mixed with dative. So instead of "Putovati sa svojima prijateljima" we say "Putovati s svojim prijateljima".