I do have a spouse who helps with that, so the dog for me is a net spoon win. I still think I get a spoon win when the spouse is away and I'm going solo with the dog, but it's easier when the spouse is here.
We don't do intensive training, though - I'm always working on a few activities but it's all very low key. So we're always maintaining old behaviors as a matter of course, and thinking about one or two new ones.
Currently: working on moderating the excessive Dance of Joy when we prep for his walk, where he "helps" me put on my shoes by standing on my feet, leaps around me in circles, etc. I got him to moderate himself for me and then taught my spouse how to get the same behavior. It's still in progress but he now lies down calmly to prompt me to get the leash on. Spouse is now getting similar results after believing it wasn't possible. (Behold the power of feedback.)
And over-enthused greetings to other dogs, many of whom don't want a dog bounding up. I'd already trained him in an automatic sit when passing humans (sitting him gets him still and smaller, so a bicyclist or jogger can pass easily), so we're working on him holding the sit around dogs and not going "hihihihihi omg hi!" to them.
We've previously done a lot of other training, and that just gets maintained naturally by doing it as it comes up and reinforcing it.
He needs weekly brushing and I do all of that because for some reason the spouse doesn't like grooming. (It's astonishingly easy with a dog brought up to like being handled; for him grooming is another form of petting.) Most service dogs are from breeds that are moderate at most on grooming needs, but they do produce some fur. We had a Shepherd mix who gave "three bags full" twice a year when he blew coat. So there's extra cleaning, which is harder on carpet and very easy on wood or other smooth flooring. I hate vacuums so found a pet hair broom with rubber bristles which gets the fur off carpet and wood alike.
I go on 95% of the walks and have the leash on the majority of those, so I'm doing all of the time consuming parts. The dog gets me exercising more than I would alone because he's so happy to go out. I do less of the feeding because my hands ache a lot so it's hard to open containers. I do all of the pilling because spouse is squeamish about feeding pills (pilling isn't actually that hard, but you have to put your fingers in the dog's mouth if the pill tastes nasty), and I take point on any first aid.
It's very personal, though. I have a brain thing where I feel supported by dogs, so they don't drain energy from me the way humans can. (I'm an ambivert.... I need human time like an extrovert, but human time also drains me like an introvert. Dogs don't drain me.)
I would suggest sitting a friend's dog when they're on a trip, or fostering a low-challenge dog for a month, to see how you respond. Go for a low energy and well socialized dog for this test - any service dog will be matched to your energy levels and have excellent manners.