iphone - no option to decline incoming calls

I'm a brand new iPhone user, after having used Android forever. I knew there would be different ways of accomplishing the same thing. But there are also so many things an iPhone just cannot do! It's been quite the frustrating journey, but I'm still trying.

I just discovered that when a call comes in, sometimes there is no "decline" button available. I've googled this a bunch and lots of people are having the same problem. Seems like a no-brainer that you should be given the option to accept or decline any call, no matter what you're doing or not doing on your phone. But apparently that option was taken away recently - IF YOUR PHONE IS LOCKED. Sheesh.

The only answers I've seen, and these are from the paid apple employees, are to double click the side button, then the red decline button will appear. As we all know, that's ridiculous!

But good news - I figured out a work around! When a call comes in while your phone is locked, your choices are accept, message, or voicemail. Just click the voicemail button, and your call is declined and it goes directly to voicemail. So essentially, just think of the voicemail button as "decline."

Otherwise, you can click "message" and you'll see choices like - I'll call you back later, or I'm busy right now... or whatever, and the call is declined and the caller is sent a text.

Hope that helps!