Blender 2.8 is definitely slower at animation in the viewport than 2.79.
I have a model of the prometheus spaceship at almost 1 million vertices. The main body being around 150,000 vertices.
In the earlier 2.8’s (interactive menu called with ‘VIEW3D_MT_object_specials’) the main body of the spaceship will animate in ‘lookdev’ at the required 30fps.(so long as the scene lights are off in the outliner !)
In the later 2.8’s (interactive menu now called with ‘VIEW3D_MT_object_context_menu’) the same main body, with the same setup, animates at around 2fps which is unusable.
The later 2.8’s print to the console for every frame …
"WARN(bke.amin.sys):C:\b\win64_cmake_vs2017\blender.git\source\blender\blenkernel\intern\anim_sys.c:3610 animsys_calculate_nla: NLA Eval:Stopgap for active action on NLA Stack - no strips case
I’v no idea if this is slowing the animation to a crawl but I am forced to use the older 2.8 versions to have any chance of animating the spaceship.