I'll be more explicit - you should test the difference. I usually recommend companies do a blackout month where they turn off all programmatic ads and then do a like-for-like comparison.

To further emphasis my point before, I've seen ad ops agencies say "hey you've got an overall 15x ROAS" and then find out that 80% of their ad spend is on-brand (give them 25x or whatever) and the off-brand (which is 20% of the spend) is giving them 5x. So their ROAS is inappropriately distributed to try to reach an overall ROAS goal.