Tusks in general just has a better offensive profile than Lando-T I think, which is more favorable rn. Rapid Spin / Ice Spinner / HR / CC has solid neutral coverage & can be difficult for teams to switch into. RS improving Tusk's speed tier is a big bonus since that lets it get the jump on some Pokemon that would otherwise outspeed it as they switch in like Enamorus. Close Combat's wide encompassing super effective / neutral coverage vs Pokemon like Rotom-W, Tera Normal Dragonite, Samurott-H etc. is quite a handy boon to have.Lando is struggling because it lacks an spamable move rn, it gets several chances to switch in but barely makes progress and just u-turns unlike when it had knock off or toxic and could cripple the rival's team. Basically it just gets chip damage over the course of the match. Tusk feels more impactful in most of the matches even if only gets the chance to knock off one or two mons or gets to spin the hazards.
With Lando-T, I don't think it packs the same offensive threat level that Tusks does because of its lack of a real secondary STAB, though I could be wrong since it does have good boosting option in SD. Still, that inability to shift speed in a meta where speed is king kinda blows.