UJM
of course Rav Chaim Kanievsky ZTL and all the Torah he learned is on a much higher level and REWARD then the MO or kollel man learning and will be rewarded much more then them and be on a much higher level in gan Eden then them also.
But someone who was born a MO person is not expected to be on the same level as a gadol Hador living and his learning and in truth guess what for a MO or reform jew to keep Shabbos it takes them more mesiras nefesh and giving things up their a regular frum yid who grew up keeping Shabbos with his family so the MO keeping Shabbos with mesiras nefesh his reward is bigger in the future world. a person is rewarded by how hard he worked for it to do the mitzvah. Ex. Building his sukkah himself versus paying a bochur to build it for him etc……