People want transformation in their lives.
They don't want a newsletter.
Stop using "subscribe to my newsletter" as your main way of getting subscribers.
Make it the secondary way instead.
The primary way should be to promise something specific they'll find valuable and helpful.
E.g.
To learn the 5 steps to becoming an in-demand wedding photographer, enter your email address and I'll send over the training video.
Vs.
Subscribe to my photography tips newsletter.