I mean, they have a few players who can go forward, but they're often being asked to basically play near their back line. If Willian is lining up more like a wing back than an attacking player, something's wrong. If Victor Moses (improvement or not) is playing significant minutes, and providing some of your offensive attack, you have problems. They've never really been a side blessed with pace, and right now, the EPL is a pace league. Spurs, City, Liverpool all win with pace. For all Jose's faults, he still has some offensive players who can get up and down the pitch (though whether that's his personal goal is a bit of a debate)
I know it's not really Conte's style, but the plodding Serie A, park the bus doesn't really win matches against a team as dynamic in attack as City. They're too good, and if you don't have the talent to punish them on the counter, you might as well just pack up shop. Throw in that Chelsea basically won't win without Kante in the middle.
They do hold some culpability for who they bought this summer. They didn't buy clear upgrades, and they didn't add support to what was already a thin squad. Some of that's due to Chelsea maybe not being willing to spend what it might take (as Roman's easing up on his investment others are spending more) and some of that is some question of the board in buying who Conte wanted. I don't blame them for having some questions, as he seemed to want some of the players he got, but they're not completely setup for long term success in the league.
As for the asked question of which job Ancelotti wants? If I'm him, neither. Chelsea, you're just as likely to get whacked by November as you are to win anything. Arsenal's a 2-3 season project. I don't think it's impossible for them to improve next season with no CL to worry about, but they've got the Europa to play in. Minimum that means they're going to pickup some injuries they don't want, or log some miles they would rather avoid. They'll have enough attack to beat up on some mediocre sides, but what can they attract with medium investment?