Most of us need 8 hours of sleep on average. 😴
What is life without even an hour of relaxation?. Maybe read a book, hang out with friends or watch a TV show. 😊
We need an hour to eat our 2-3 meals, shower, poop etc. 🍴
Most of us have chores (or people) to take care of - cooking, dishes, washing clothes, tidying up. Let's set aside an hour for that. 🧹
We need to take care of our body. Let's take 30-60 mins of exercise. 💪
🏁 We are halfway through the day! 🏁
Note that all these activities are kind of essential to survive, not just now but for the rest of our lives. If you have an existential crisis, you should have just half an existential crisis with this realization :).
We'd do a lot better with those remaining 12 hours if we took some time to plan the day, meditate, set intentions and goals. 🧘
Unless you are wealthy, you probably need to work to make a living. Let's say you work for 8 hours a day. Many people work 10-12 hours, which would just take up the rest of the day. 
Most people commute to work or to do chores/hobbies for 1-2 hours pre-COVID. Hopefully that goes away for good.
You are left with 1 hour to pursue a hobby.
If you are a parent, you are probably spending that time with your kids instead of hobby.
Weekends are a bit more relaxed. We get more chores done and enjoy meals with friends and family. There's also plenty of hours left for hobbies or relax
That seems easy and balanced! Why does life feel so busy?
Lack (or complete absence) of planning is a common reason. Distractions and lack of disciplined follow through is another. Most of us lose focus a lot, spend time scrolling on our phones or watching movies.
📱📱📱!
How to make better use of the 24 hours?
Plan your days and eliminate distractions. Set fixed time, preferably towards the end of the day, to scroll through your news feeds or watch Netflix.
Shorter commutes make people happier (link). Live close to work or work remote; create a gym at home. If you can't fully eliminate your commute, you can try to make it more relaxing or productive.
Compound activities: choose activities that meet multiple needs for you. For e.g.: You can choose a work that pays that is also a hobby and feels relaxing, so you essentially spend all your free hours doing exactly what you want. Biking be a hobby that also relaxes you and keeps you fit.
You could work fewer hours by increasing your focus or efficiency, or by reducing your income. You can make more per hour of work by becoming more skilled or doing more work in few hours by being efficient. You can also work part-time and choose to forgo money for more time. 
You should also try to do activities well and get better at doing them. Some ideas:
One final note
These 24 empty boxes are all you have. Your life is what you fill them with. Use them intentionally and wisely.
*****
Addendum
I stumbled on this survey of how Americans spend their day from the Department of Labor.
