Is Poppy still good building pure damage?

No

Her E and Q will hit pretty hard though, a full combo would kill an ADC like before, but it's definitely not like before. especially without her old passive

No. She's been changed to more a utility champ then damage. She does better with a tanky build. And learning her E into Q combo is where your damage comes from now.

She has bad attack speed and does less damage with Q.