It's because they have seven different models of everything, nobody knows what the difference is between them
The current lineup is really really confusing for the average consumer... and that's the customer they target. I think a combination of upselling and genuinely wanting to make something for everyone.. they have ended up here.
I feel the point at which they start to cut back on models is coming soon... it happened before, and it will happen again.
Apple want to be about simplicity, premium and things that just work. They kind of lost that a bit in the past decade or so.
Really, they only need two tiers in each category... regular and "Pro". And, if I think I know they are the company they want to be... the regular device should not skimp on quality or design.
I do like it that they offer the Apple Watch SE... as it does most things for most people.
The Mac lineup is pretty decent... but the Mac Pro is just not enough considering its cost... most people don't even need to go there... they should have made the Mac Studio the Pro and designed a special interconnect/expansion system (like with the eGPU of past). The just need to stick with MacBook and MacBook Pro, Mac mini, iMac and Mac Studio.
I don't like the iPhone lineup... their cheapest iPhone, the current SE is just too little as a product, its battery, camera and display are just too outdated compared to the next model up. If they made a quality iPhone that sat between the SE and regular, and just had that as the regular, and then a Pro version... it would be way better.
I don't like the current iPad lineup either, it's way too complicated and the design choices for pencil and keyboards are appalling for such a big company with a massive cash pile. The iPad is way too gimped compared to the Air... to be honest it should be iPad and iPad Pro.
Im sure in the next few years they could refine and simplify the lineup and make the amongst the best devices in each category on the market. Apple used to just make one device, and make it the best it could be... they need to go back to that.