If you add together the total runtime of parts 1 and 2, and compare it to the total runtime of the SciFi miniseries, they're almost identical, but the SciFi miniseries included almost all the content from the books, and Villeneuve's movies left a ton out, which destroyed the lore and story.
Even worse. The miniseries is almost an entire hour shorter.
Even worse. The miniseries is almost an entire hour shorter.