Kante job is not easier given the reason you gave, but definitely less responsibility demanding as if he can't do that, Chelsea can easily switch to a more possession base with Cesc, adding more work rate in place of Hazard with Willian. Pogba has no responsibility to do since taking him out, we're back to uninspired slow midfield that last few seasons: Carrick, Bastian, Herrera, Fellaini, Rooney. Adding workrate & a bit of space would mean you use Lingard, Young, Valencia (can add Rashford there too but he's very defensive suspect beside the workrate) on the wing/ attacking position. Look at that team without Pogba, the lack of energy, dribbling through central midfield, penetrative chance creating pass (better than Carrick)... is obvious.
The doing the job of 2 midfielders is exaggeration. His workrate, the ability to pressing is impressive. He covered more ground is to get the best out of him. Not like player can take off a player whenever they want; or there are teams that were able to beat this 12 men team. If this is what the football is all about this then Barcelona would have gone extinct long ago. The tiki taka concept was to counter the physical demand as Spanish & Latin players don't have the physical attribute & stamina as big as some other part in Europe. There are players out there who run as hard, but also offensively better (Vidal, Nainggolan), can anyone say their team played with 12+ players & they can make 10 men formation & add a luxurious player?
Pogba was serial winner with Juventus & getting due recognition as key player, so the bolded part is not the way to judge players.
The idea is always with double pivot with Pogba being part of it from the start. Circumstance leading to midfield 3, but then when thing lighten up, Mourinho would like a midfield 2 & ultilize the no 10 role as the play making focal point of the team, not Carrick deep play maker.