Mac OS
A solid reason to switch to Mac from Windows PC is Mac OS. Based on Linux, offers more stability and better security than Windows but you will not be able to find a vast array of applications on it.
Even when Mac OS X (the first big one) was first introduced, it looked and felt like ages beyond Windows (Microsoft just recently made a slick and modern design with Windows 11). Under the hood, it turned out that the operating system itself is stable and incredibly fast & responsive. If you value stability and easiness of use, Mac OS is the Operating system for you.
Apple ecosystem
This one is easy, if you are already invested in apple devices like iPhone and iPad, having an apple computer is one step forward into the apple ecosystem and one more step into easy sharing of documents and data between devices.
Calendars, emails, photos, videos, documents, and many more can easily be shared and synched between devices with a single apple ID making workflows much easier than on other operating systems.
Development
Developers all around the world say that developing on Mac is much better and smoother than on PC, this has probably to do something with OS being based on Linux but whatever the case is, it is much smoother and it just feels better. Apple laptops are often the go-to choice of developers for a reason.
Also if you are in the development business for applications and services aimed at iPhone or iPod then there is no really another way than to be into the apple ecosystem and own apple hardware.
Professional software
A lot of professional-grade software exists for both the Windows platform and Mac OS but there is some software that exists exclusively for Apple hardware like Final Cut Pro or Logic Pro. Both applications are used by professionals and are industry-standard software.
Logic pro is used by industrial audio specialists all around the world and is used in professional studios. Final Cut Pro is also used worldwide by video editors and if you are specializing in any of these two fields Mac seems like a very reasonable platform since the software can not be found on Windows. These two are examples, there are other similar applications that are only available on Mac OS
Longevity
Apple hardware is made of high-quality materials and components and it is proven over time that it lasts longer than usual. There are iPhones out there that have 13 years and they are still working, G3 and G4 Macs that are still functional.
When buying Apple products they will outlive other ones if treated properly so in the end you could be saving money by purchasing them.