Watches, especially mechanical ones, are jewellery: objects of desire, not of need.
They are relatively terrible at keeping time, expensive to buy and you need to be preoccupied with their upkeep.
There's value in having a simple watch, in the quiet comfort it provides when checking the time without being distracted by notifications, but any Timex or $50 Casio (great watches also btw) will do the job better than any mechanical watch ever could.
It's an obsession and a hobby, but rationally indefensible.
Like socially acceptable hobby train collecting, only you strap the train on your wrist and flaunt it about for social signalling with the pretense of needing a Vacheron Constantin to tell the time.
You don't need it any more than you need cufflinks to button the sleeves of your shirt.
If you're lusting after a watch you can't afford you can calm that desire by reminding yourself of the irrationality of it all.
Or, if you do decide to give in, then lean fully in, instead of trying to justify it with thin veneers of rationality: I'm giving myself a present. For a certain type of person that's a very hard proposition.
I'm saying all that as someone currently wearing a mechanical watch.