I feel the same way as you at least for the Apple Watch. I used my apple watch sport series 2 for around 6 months with a protector and then I took it off. Kept it that way all the way till the series 4 was announced and then sold it. haven't put one on my series 4 and won't (but I did just buy applecare since I workout and swim a lot with my watch and bang it against hard surfaces like the pool edges all the time).
With that being said I've always used TechArmor for their glass screen protectors and excellent replacement warranties for my phones and tablets. I have one on my iPhone X and I
had one on my 1st gen iPad Pro 12.9 for nearly 3 years. It works great on my phone. But I was having touch sensitivity issued on my iPad Pro 1st gen since upgrading to iOS 11 strangely when it released. Then when I upgraded to iOS 12 almost all the touch issues disappeared. Then I sold my iPad and bought the new 12.9" pro.
I ordered this screen protector from TechArmor for my new iPad that I'll finally be able to play with tomorrow when I get home from my dorm:
https://www.amazon.com/gp/product/B07H448JKS/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1 but it doesn't ship for over 2 weeks. So for the first time I'll be using an iPad without a screen protector. I specifically ordered this one because it has a notch for the sensors and I know TechArmor stands behind their products. I'll see how it goes without using a protector and may just return the screen protector when it arrives.