I don't know about Siri, but I do believe Google Home has gotten worse. My girlfriend and I mostly use it only for things like turning lights on and off, pausing/resuming the chromecast, setting timers, and asking for the weather.
I've noticed it's been misunderstanding my girlfriend more and more over the past few months (she has a slight accent to her English, but nothing remotely difficult to understand), and lately it's started misunderstanding simple things that I say too. For example if I have Netflix paused and say "hey google, resume", 30% of the time it will give me search results for how to write a résumé instead of unpausing Netflix. I've had the Google Home for a few years now, and that literally has never happened before now. To get it to work reliably, I have to instead say "resume playback" or "resume chromecast".
I've noticed it's been misunderstanding my girlfriend more and more over the past few months (she has a slight accent to her English, but nothing remotely difficult to understand), and lately it's started misunderstanding simple things that I say too. For example if I have Netflix paused and say "hey google, resume", 30% of the time it will give me search results for how to write a résumé instead of unpausing Netflix. I've had the Google Home for a few years now, and that literally has never happened before now. To get it to work reliably, I have to instead say "resume playback" or "resume chromecast".