Should you, as a writer, adopt the policy of writing every day? Forcing the words out, if necessary, putting down word after word without joy, without weight and without meaning? Is there really any benefit to that?
Most in the writing industry will tell you that writing - good writing - comes from practice. They will actively encourage you to write each day. They will insist on it. Only through such good habits and developmental practices will you improve.
But is that always true? Should you always write - even when you don't feel like it?
The big question here comes down to you - you as a writer.
What differentiates a Writer from a writer (note the capitalization) is pretty well the same thing that differentiates an Artist from an artist.
A Writer (capital) is essentially an Artist (capital) because they literally live, eat, drink and breath their work. The thought of not producing that work is unimaginable. They literally are born to perform, so to speak. It's not so much a matter of a Writer writing than being a channel for the writing. Try to stop breathing - it's easy. OK, well it isn't easy, but it's about as easy as it is for a writer to stop writing.
If you are not driven then you are not a Writer. Or an Artist.
So having said all that, is it necessary to write every day?
The short answer is that - when the urge to write occurs - it is impossible to not write every day. If you don't do it then you feel incomplete.
At least, most days.
Some days even Writers don't have the urge.
And on those days, they do not write.
Which I think answers the question.