You want Apple to put more mics into the iPhone, so that it can better address a use-case that Apple is already addressing with a well-engineered product built expressly for that purpose?
OK.
When a timer stops, for example, I want to be able to say "hey Siri stop timer."
It’s perfectly acceptable if Apple doesn’t see this as a use case. I’ll simply take my business somewhere else to solve that problem. I'm simply throwing it out as a nice to have.
Is this a problem you have? I'm able to reliably use Siri on my phone from up to maybe 2-3 feet away in a moderately noisy environment (casual conversation around a table) with almost no issue, and I can easily use it up to 10+ feet away in a quiet environment. I've had this success since the 7+ at least (when I tested it), but I've continued to see such performance on the X and XS Max.
“Hey Siri, create a 10 second timer”
“Hey Siri, play some Rolling Stones”
Find yourself picking up the phone to stop these two actions?
I understand that you would like "Hey Siri" to be better. What is not clear to me is how you think Echo Dots are a "competitor" to your phone. Echo Dots are purpose-built Home Assistant hardware. Just like the HomePod. No phone is going to perform nearly as well as a purpose-built home assistant -- it's a hardware limitation. No matter how many mics you put in any phone, the far-field performance is not going to be great. It's like you want your sedan to be just as good at carry heavy loads as your pickup truck. That's ridiculous. And as far as Home Assistants go, the HomePod's mic/noise setup is hands down the best.
So if you find yourself constantly asking questions of your phone while its sat down in your living room or kitchen or bedroom or wherever it is you're setting timers and playing music (I'm going to bet it's the kitchen), buy a HomePod for your kitchen. That is the solution to your problem.
Or you could get Google Home products. They are also better than the Echo line. Sounds to me like you're just disappointed you bought the worst Home Assistant products on the market.