Well, quick look at whoscored:
Giroud's nonPG/90 is .9 in 900 min of league play. Ronaldo's is .6 in 2100. Giroud's got 1.0 key passes to Ronaldo's 1.1. Both are null as dribblers, Ronaldo just tries it more and loses it more; averaging .9 dribbles and 1.3 unsuccessful to Giroud's .1 dribbles and .1 unsuccessful. Ronaldo edges Giroud in PS% 79.1 to 71.3 (logical as Ronaldo faces the play a lot and Giroud plays with his back to it; it's a mediocre-poor figure for both considering).
It's not a laughable comparison at all. Both are quite limited players whose sole contribution to the team is goal-scoring--Giroud's is well-superior...the fact that Ronaldo plays nominally on the left and Giroud strictly through the centre probably evens out with the fact that Madrid is much better than Arsenal--and who are detrimental to the team often in build-up (Ronaldo because he's selfish and takes a lot of shots which don't result in goals and end attacks, or dribbles that end attacks--which can be seen in his 5.8 shots/90 to Giroud's 2.9, while Giroud of course scores at the far better rate. Giroud because he loses possession a lot, though he's also asked to hold the ball up in ways Ronaldo is not)
I was going to say Ronaldo probably has superior movement to Giroud but his goal scoring figures this season, at least, do not back that up.
Me discrediting Ronaldo has never backfired on me. I pointed out his decline a while ago when people still hadn't caught on to it. I've always avoided the discussion of Ronaldo/Messi--because the comparison or illusion of there being an actual discussion/choice between the two is harmful and confusing to the many little minds of the world, a bit like Hillary/Trump--instead preferring to compare him with whoever was the 3rd best player in the world before he began his precipitous decline to Olivier Giroud-ness.