Diabetics are allowed to not fast. The old, the ill, the young, travellers, and women menstruating or pregnant are also allowed to not fast. Moreover, people with extraordinarily difficult manual labour jobs are allowed to break their fast - given that they redo those days on their days off. If it puts your health in serious harm, don't fast.
However, elderly who are capable do fast. Athletes do fast. Even children do fast. Most people want to participate because it's a community celebration. I grew up in a Muslim country, and Ramadan is a month I've always enjoyed. Friends, neighbours, and family visit each other. Everyday we receive food parcels from half the neighbourhood, and we send out an equivalent amount. Halfway through the month we have Nasfa, which is basically Halloween but we wear traditional clothes and go house to house collecting candy. This is then followed up with Eid 2 weeks later, which is a 3 day non-stop celebration. It's the most commercial month of the year. Restaurants are packed. Every TV channel comes out with dozens of 30-day series. People stay out till dawn. It's also the month when the most charity is given in the Muslim world and a lot of volunteering also occurs during this month.
It's also a very spiritual time. I still fast, despite my lack of belief, like I've done since I was a child. I feel calmer, and more meditative in my everyday life. I use this month to cut out most of my bad habits and vices, which ultimately is harder than depriving yourself of food. It's a time when you spend more time thinking about the struggle of the less fortunate. The feeling of deprivation from food, water, sex, and many comforts of the world really incentivizes you to give more. It motivates you to be a better person continuing throughout the year. When I was religious, I used to spend my time quite similarly: participating in prayer, study, and recitation.
Of course there's also drawbacks: I tend to lose a lot of weight this month due to only eating a single meal most days. My appetite noticeably shrinks, and I feel more sluggish. I'm healthy and I'm still able to perform my job fully, go for walks, and participate in activities, albeit more sluggishly. I've studied this a bit by using my completion velocity for tasks when I'm fasting versus when I'm not and haven't found conclusive results yet. Last year, I underperformed my normal velocity by 5%. This year I outpaced it by 3-4%. I believe the difference this year is better meal planning.
Towards the end of the day, I'd get cranky due to dehydration and lack of sugar. Oddly enough, a lot of people go the other way and gain weight by binging after sunset. It's quickly becoming a very commercial season, where all consumption and materialism are kicked into overdrive.