Liverpool have had injuries of a significant level. They're just better equipped to weather them.
Matip has basically been out much of the season, and while not Laporte's level good, he had played at a superior level down the stretch for most of last season. Throw in both Gomez and Lovren being hurt. If Virgil was to get hurt, it would make a big deal, but they've got 3 other central defenders who vary from decent/passable (Lovren) to pretty good (Matip) to excellent (Gomez).
Alisson missed most of the first part of the season. Liverpool basically went with a guy off the street from the first league match.
Fabinho was Liverpool's best midfielder, and probably is one of the best holding midfielders in the world, and they weathered it. Heck, they've had a bit of an uptick. Keita has been in and out of the lineup his whole Liverpool career, even when he showed spurts of being a dynamic option.
Mane's out now. Ox is only recently back, and still getting fitness. Milner hurt.
Sure, they've been lucky in some areas, but Liverpool have continued to roll even with big injuries.