I guess it sort of depends on your definition of hassle.
When I used cartos, I had to fill them and add juice as necessary to keep them filled. If I was feeling particularly cheap, I had to clean them. When they were used up, I had to discard them and replace them. I had to order replacements...
When I used commercial attys, I had to blow them out fairly often. I soak them in vodka and dry burn them. Some lasted a while, some didn't. The "good" ones were somewhat expensive. I had to order those to keep in stock too.
When I switched to rebuildable attys, I ordered a bunch of cotton and wire... Won't have to order anything for those for several years. To clean, I pull the wicks and run under a warm tap... re-wick and put back together. Now and then a dry burn might be required. Every few weeks, I have to wrap some new coils. For that, I just wrap some wire around a screw I found on my desk.... and if I want better looking coils, the Kuro jig is dandy. Every few days, I replace the wicks.
The most hassle-reducing thing I ever did for my vaping was get a REO and the second most hassle reducing thing I ever did was get an RM2 rebuildable for it. I fill my bottle and switch my battery once a day. That takes about ~1 minute. About once every 3-5 days, I replace the wick. That takes about ~2 minutes, sometimes 3 if I don't put my reading glasses on first. About every 5-6 weeks, I replace the coil. Wrapping a loose 1 ohm coil on a screw takes about a minute and another minute or two to install and then a minute to wick it (all assuming I found my glasses first). Wrapping a perfect coil with the Kuro takes about 20-30 seconds and the same amount of time to install and wick.
Without going totally disposable (there are many disposable cig-a-likes on the market) and just tossing the whole thing when it is used up, there is no such thing as vaping without putting in any effort. I have seen no disposables that advertize sub-ohm (probably because their batteries can't handle that sort of stress), so I don't think there's any sub-ohming with zero effort put in to it.
So, though I'll guess you get some varied answers, the truth is that there is always going to be *something* to do that you might consider a hassle to get a satisfactory vape.