As Liam suggested run the project second time.
Plywood will work but had problems. The main problem is each ply is 90 degrees from the previous ply. The top veneer is usually thin. Many cabinet grade plywoods have voids in middle layers which can show up in project.
Baltic birch is better quality but is hard to get right now. Not all plywood is good quality. It looks good on the face but underneath may not be good.
I prefer solid wood but plywood is good if you choose wisely.
Recently I posted about baltic birch availability. Several suggested ecylyptus and appleply and a few others. Search on forum for ecylyptus and read replies.
Whenever possible use downcut bits. Vee bits are not made on downcut but any flat endmills try to use downcut.