Being a professional is more about how you conduct yourself than the exact way you take a photo.
My pro manual argument for myself is that it’s actually one more variable to deal with in terms of getting the images to look exactly how I want.
ISO/Aperture/Shutter Speed
OR (using A-mode as the example) - ISO/Aperture/Exposure Compensation/Metering mode.
And if I make a mistake in manual, it’s my fault and I can learn from it. If the camera guesses the scene wrong, it will never learn.
I can’t say that feeling will go away ever. Your photography will improve if you keep doing it and attempting to learn and improve in some way.
Although I may always feel like that, I do cherish the experiences that photography has brought me, the things I’ve seen and done, the feelings of excitement when I do like a photo, even if it doesn’t last (or come until well after I took them). I do like how it’s changed how I see and interpret the world.
For like a year I dabbled into food photography as a hobby and really tried to go as deep as I could down that rabbit hole in my spare time. Youtube, some books, etc. Trying to make photos every chance I got.
Although I have done years worth of professional work, and knew how to light, etc., the very pre-meditated, small scale, thoughtfully lit food photography really upped my game in a number of areas.
I think there are a lot of people that learn about editing style or shooting formats, rather than content (subject, emotion, moment, composition, lighting and other in-camera techniques, etc).
And if those fundamentals are weak, it can feel like putting a coat of paint on a crumbling structure. The paint is great if there’s a strong foundation, but without it…