As you said, those titles were announced few years ago when companies still had hope the Vita would go somewhere, but it flopped just like the WiiU. Other than the PS4, what other platform can they focus on that is actually worth making money on that isnt mobiles or PC? 3DS and Switch.But Dragon Quest titles sold well on the Vita and they announced Dragon Quwst XI around that time. Vita has tons of first part support, those Assassin's Creed and Call of Duty games weren't free. Sony ported Borderlands 2 and Resident Evil Revelations 2 themselves.
Switch is effectively the next Vita but without the downfalls that the Vita had like expensive memory cards and lack of first party support.