For personal projects of course, we can do whatever we want. But I don't make a living with personal projects. I do that by working for a company 8 hours mon-fri, and there I am not in charge of the tech stack used.
- Page navigation becomes easier if you know the server can handle any route you throw at it as a launch point.
- You can get by with cheaper end-to-end tests for critical flows by not using Javascript in your test suite (although you should be careful to use it when it's important)
- You get a degree of protection if something does go wrong on the front end that you get a non-JS experience to fall back to.
- Pages that genuinely don't need Javascript (think like simple CRUD forms) don't have to pay the SPA tax.