Yes, for ordinary words, I believe every language assimilates them after some time. But I was talking about names. No Czech would in their right mind write Čarl

Yes, for ordinary words, I believe every language assimilates them after some time. But I was talking about names. No Czech would in their right mind write Čarlí Čeplin even after many decades. So let's not do that with Čapek in English either. Let him be written Čapek (or Capek due to the limits of our keyboards), but pronounce [Chapek], remembering he is Czech.