Some offices give employees time off during holidays, but others don't. Some even make employees come to work on Christmas Day or during other festive seasons.
For me, I don't think it's fair to make an employee work during holidays. I think it should be voluntary - if you want to come to work, you can, but if you don't, you can stay home and celebrate with your family and friends.
Giving employees official holidays during their festive seasons should be part of their benefit package. I say "their festive seasons" because Christians may want to celebrate Christmas, Muslims may want to celebrate Eid al-Fitr, and Hindus may want to celebrate Diwali.
This is also a way to promote diversity in the workplace. If Christians take Christmas off, Muslims and Hindus can work, and then when Muslims take Eid off, Christians and Hindus can work. This way, you can regulate your workforce and give employees the freedom to celebrate their holidays.
By doing this, you prioritize employees' satisfaction and well-being. This is why people don't leave jobs, they leave toxic work environments. When you make people feel comfortable and loved, they will stay, and it will increase productivity and mutual respect.
Closing offices during holidays for like two weeks might affect business revenue, but how much?
You've been working from January to December, you should have sustainable investments and is it worth making employees miss out on time with their families and friends? I don't think so.
But what do you think about making someone's work mandatory during holidays?
Work is not some voluntary fun time that you are donating charitably - it involves tasks that you are required to do in exchange for money. You meet the expectations of the business and agree a contract, at that point if you feel that the holiday is not flexible or meeting your expectations, you are free to negotiate and may get what you want - which is presumably set days off each year. You better have a lot to offer if you want some sort of special contract not received by everyone else. You'll get a certain amount of days off each year, which may or may not include public holidays. If you don't get public holidays off or the religious days off that you want, then you're free to book them in advance like anyone else. It's a really simple system that you've tried to over complicate.