Although the answer depends on the situation, in general, and under normal circumstances, I don’t think it is genuinely viable to keep a domestic cat confined to your home full-time why you work away from the home full-time. For me, this is a recipe for your cat to become stressed and develop health problems as a consequence. Often cat owners are blind to what their cat’s does throughout the day when they are away all day, sometimes for long hours. They may be surprised to find out. It is likely that their cat will show signs of stress and distress. But this is a debate about cat caregiving standards. I set high standards. Perhaps unreasonably high. But I can because I am retired. I am at home for as long as I want to be. However, if you set low standards, it is fine to keep a cat in an apartment all day while you are out for ten hours, 5 days a week.

I just don’t think it works. When you think about it, it can’t work. You’re leaving a cat confined to a home, sometimes an apartment, for 10 hours a day. They are entirely alone. Often the home has no environmental attributes in terms of stimulating a cat mentally. This is an environmental desert in terms of the requirements of a domestic cat. Life is better for zoo animals. At least they see zookeepers and visitors.
And no doubt, too, the cat is being fed dry cat food around the clock because it’s convenient as it won’t go off. That’s another plank in the edifice that is heading towards failure. I’m probably exaggerating. Many cats will survive this situation. And for many this life is better than their previous life; abandoned and dying. They will get by but they may develop cystitis which is described as idiopathic cystitis. Another term for this disease is lower urinary tract disease caused by stress.
I should know about these things because I did it myself. For a number of years, I worked full-time, long hours as a solicitor while my cat was at home. For a while she was in an apartment. I gave her dry cat food. I was a failure as a cat owner at that time. There is no shirking that conclusion.
I get the problem, however. The person wants a cat because they love cats and they want a companion. The motives are good but their circumstances are not. I don’t want to sound too strict and demanding but sometimes cat lovers are not in a position to properly care for a cat. They should exercise self-discipline and wait until they are able to discharge their responsibilities to a good standard.
When adopting a cat, the adopter should ask some tough questions. Adopting a cat is not automatically a good thing for the cat. And that applies to rescue cats. Many adopters are not in the right state of mind to do a good job. Neither are they in the right situation in terms of their lifestyle and circumstance to do the job properly. They should not adopt. They should resist.
I would estimate that about 10-20% of cat owners are unsuited to own a cat which is why we have so many cats in shelters. It is why we have unwanted cats and cats abandoned. It is why we have informal, careless breeding of cats. It is why we have cats dying in house fires when the owner gets out. It’s why we have people operating cat rescues from their home when the house catches fire and all the cats die while they are outside watching. I’m being tough but the standards are not high enough.
When the wild cat was first domesticated there were no feral cats and yet today, in 2021, there are about 250 million or more feral cats in the world. All of them were unplanned and all of them are unwanted. Some are cared for very tenderly by volunteers. Many are community cats so they get by with the help of decent people such as shopkeepers feeding them. But they shouldn’t be there and they are there because of irresponsible cat ownership.

A guy on the Reddit.com website asked about getting another cat because he works full time and his cat was a full-time indoor cat. This is his question. His cat is above:
Do I need to get my little guy a friend? I need advice he is 10 weeks I work full time. He gets left during the day ;( he will be a house cat. So is it best to get another one?
He’s asking whether he should get another cat and the answer is yes provided the cat gets along with the existing cat. An obvious condition, I know, but I read too many stories of slightly or greatly dysfunctional multi-cat homes where there is tension between the cats. I call that a failure.
If when cats are left alone all day, are two cats better than one? Is that the solution? I don’t think it is. It’s a partial solution but I still don’t think it’s good enough because you have two cats who are left alone all day. You might have two stressed cats. They can entertain themselves to certain extent but they need human companionship because they are domestic cats. Domestic cats are socialised to people. They are deliberately socialised to people. They are acclimatised to being around people.
The bottom line as usual is about standards and thinking of cat welfare and respecting the cat when adopting. What are our standards of cat caregiving? How high should they be? Personally, in general, I feel that they are too low.
It’s a highly responsible step for a person to take. It should never be taken lightly. The commitment is for the life of the cat. Boring perhaps for some but essential.