You do know that Apple also has their own R&D. The different is Apple don't always tease or showcase their prototype to the public like other companies do to be the first (except for several products), making people think that Apple always late to the party.Samsungs doing all the R&D and heavy lifting. In a few years when Apple releases their own folding phone, they'll take all credit and Macrumors will actually give them all the credit.
Happens all the time.
Apple probably has their own version of folding phones / tablet in their lab right now from years of research but they didn't show or release it when they think it's not ready. Example: the M series chip, you think how many years they took for the research in their lab before they think it ready for release, and how many other chips & experimental products that we don't know are being research.