If you're comparing short-term profits it might be significant, in that it could indicate whether the profits indicate sustainable growth or just "eating the se

If you're comparing short-term profits it might be significant, in that it could indicate whether the profits indicate sustainable growth or just "eating the seed corn" via R&D cost cutting which sacrifices future profits. Though over a long period (but how long? years? decades?) it shouldn't matter, since as you point out if past R&D expenses were effective from a business POV they should be reflected in future profits.