For those who say the Celtics path is easy, I like to point out that seeding matters. The Celtics earned the #1 seed while other teams like Miami, the Lakers, and even the Bucks rested, coasted, or just flat out were inconsistent during the regular season while they believed that seeding was not important and they would turn it on in the playoffs.
Second of all, depth matters. The Sixers, Knicks, Bucks and others had key guys missing significant time in the regular season and playoffs, and that was devastating for them. The Celtics roster can afford to have one of the key guys out and still compete with anybody.
Are we fortunate so far, yes of course, but this has also been due to Stevens and Mazzulla and the players not taking things for granted, building the right roster and taking the regular season seriously.